Headache syndromes

1. 
   

   Migraine

   
   
   
   
   1. 
      

      aka trigeminovascular syndrome

      
      
   2. 
      

      Paroxysmal headache (HA) associated with multiple signs and symptoms that can overlap with sinus symptoms

      
      
      
      
      1. 
         

         Unilateral

         
         
      2. 
         

         Throbbing pulsatile headache in the frontotemporal or orbital area

         
         
      3. 
         

         Aura

         
         
         
         
         • 
           

           Can arise before or during the HA

           
           
         • 
           

           Usually visual but can be sensory or motor

         
         
      4. 
         

         Pain builds over 1 to 2 hours and progresses posteriorly

         
         
      5. 
         

         Headache lasts 4 to 72 hours

         
         
      6. 
         

         Photophobia, phonophobia

         
         
      7. 
         

         Nausea—80%, vomiting—50%, anorexia and food intolerance and light headedness

         
         
      8. 
         

         Signs

         
         
         
         
         • 
           

           Cranial/cervical tenderness

           
           
         • 
           

           Horner syndrome

           
           
         • 
           

           Conjunctival injection

           
           
         • 
           

           Tachycardia or bradycardia

           
           
         • 
           

           Hypertension or hypotension

           
           
         • 
           

           Hemisensory changes or hemiparesis

           
           
         • 
           

           Adie’s-like pupil (light-near dissociation)

      
      
   3. 
      

      Diagnosis

      
      
      
      
      1. 
         

         Two of the following characteristics

         
         
         
         
         • 
           

           Unilateral location

           
           
         • 
           

           Pulsating quality

           
           
         • 
           

           Moderate to severe pain

           
           
         • 
           

           Aggravated or caused by physical activity

         
         
      2. 
         

         During the HA patient must have one of the following

         
         
         
         
         • 
           

           Nausea and/or vomiting

           
           
         • 
           

           Photophobia and phonophobia

      
      
   4. 
      

      Imaging

      
      
      
      
      1. 
         

         Diagnostic imaging is not necessary in patients with stable history of migraine headaches and a normal neurologic examination.

      
      
   5. 
      

      Management recommendations

      
      
      
      
      1. 
         

         CT is not recommended for headache evaluation when MRI is available, unless in an emergency situation.

         
         
      2. 
         

         Persistent over-the-counter (OTC) pain medication for the treatment of unrelenting headache is not advised as this symptom may indicate underlying brain pathology.

         
         
      3. 
         

         First-line treatment of migraine should not include opioid or butalbital-containing medications.

         
         
      4. 
         

         Lifestyle modifications

         
         
         
         
         • 
           

           Avoidance of carrying heavy purses or bags over one shoulder

           
           
         • 
           

           Avoidance of certain foods

           
           
         • 
           

           Maintaining hydration status

           
           
         • 
           

           Sleep hygiene

           
           
         • 
           

           Limit stress

         
         
      5. 
         

         Integrative medicine

         
         
         
         
         • 
           

           Magnesium

           
           
         • 
           

           Riboflavin

           
           
         • 
           

           Coenzyme Q10

         
         
      6. 
         

         Abortive medications

         
         
         
         
         • 
           

           These medications aim to reverse or at least stop the progression of a headache.

           
           
         • 
           

           Most effective when given within 15 minutes of symptom onset when the pain is mild.

           
           
         • 
           

           Types

           
           
           
           
           1. 
              

              Triptans: selective serotonin receptor agonists

              
              
           2. 
              

              Ergot alkaloids: ergotamine, dihydroergotamine

              
              
           3. 
              

              Analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs)

              
              
           4. 
              

              Combination medications

              
              
              
              
              • 
                

                Acetaminophen, aspirin, and caffeine (ie, Excedrin)

                
                
              • 
                

                Butalbital, aspirin, and caffeine (Fiorinal)

                
                
              • 
                

                Isometheptine, dichloralphenazone, acetaminophen (Midrin, Duradrin, and others)

              
              
           5. 
              

              Antiemetics

         
         
      7. 
         

         Prophylactic medications

         
         
         
         
         • 
           

           Indication

           
           
           
           
           1. 
              

              More than two headaches per month

              
              
           2. 
              

              Duration of headache is more than 24 hours

              
              
           3. 
              

              Significant disability for equal to or more than 3 days

              
              
           4. 
              

              Abortive therapy fails or is overused

              
              
           5. 
              

              Abortive medications used more than twice a week

           
           
         • 
           

           Types

           
           
           
           
           1. 
              

              Antiepileptic drugs

              
              
           2. 
              

              Beta blockers

              
              
           3. 
              

              Tricyclic antidepressants

              
              
           4. 
              

              Ca²⁺ channel blockers

              
              
           5. 
              

              Botulinum toxin: up to nine treatment cycles for progressive improvement in symptoms

   
   
2. 
   

   Tension headache

   
   
   
   
   1. 
      

      Most common type of recurring headache thought to be related to muscular factors and psychogenic forces (stressful event).

      
      
   2. 
      

      Throbbing quality with onset more gradual than migraines; usually tension headaches are more constant and less severe.

      
      
   3. 
      

      Headaches can last up to 7 days.

      
      
   4. 
      

      Not associated with nausea or vomiting, photophobia, and/or phonophobia.

      
      
   5. 
      

      Diagnostic criteria

      
      
      
      
      1. 
         

         Two of the following must be present:

         
         
         
         
         • 
           

           Tightening in frontal-occipital locations

           
           
           
           
           1. 
              

              Occipitonuchal

              
              
           2. 
              

              Bifrontal

           
           
         • 
           

           Bilateral

           
           
         • 
           

           Mild to moderate intensity

           
           
         • 
           

           Not aggravated by physical activity

      
      
   6. 
      

      Management

      
      
      
      
      1. 
         

         Imaging is only required if headache pattern changes and is not a common primary headache disorder, such as migraine, cluster or tension headache

      
      
   7. 
      

      Treatment

      
      
      
      
      1. 
         

         Massage, relaxation techniques

         
         
      2. 
         

         Lifestyle modification: regular exercise, balanced meals, adequate sleep

         
         
      3. 
         

         Trigger points injection/occipital nerve block

         
         
      4. 
         

         NSAIDs

         
         
      5. 
         

         Tricyclic antidepressants, muscle relaxers

   
   
3. 
   

   Cluster Headache

   
   
   
   
   1. 
      

      Group of headaches (known as histamine headaches) with multiple characteristics

      
      
      
      
      1. 
         

         Severe unilateral pain that is orbital, supraorbital, or temporal.

         
         
      2. 
         

         Each headache lasts 15 to 180 minutes and can occur eight times a day or every other day.

         
         
      3. 
         

         The HA may occur 1 to 8 times a day for as long as 4 months.

         
         
      4. 
         

         HA are often nocturnal, during sleep or early morning hours.

         
         
      5. 
         

         Associated with one or more of the following ipsilateral signs:

         
         
         
         
         • 
           

           Conjunctival injection

           
           
         • 
           

           Lacrimation

           
           
         • 
           

           Nasal congestion

           
           
         • 
           

           Rhinorrhea

           
           
         • 
           

           Facial hydrosis

           
           
         • 
           

           Miosis

           
           
         • 
           

           Ptosis

         
         
      6. 
         

         Two main forms of cluster headaches

         
         
         
         
         • 
           

           Episodic: at least two cluster headache phase that last 7 days to 1 year are separated by a cluster-free interval of 1 month of longer.

           
           
         • 
           

           Chronic: cluster occurs more than once a year without remission or the cluster-free interval is less than 1 month.

      
      
   2. 
      

      Management

      
      
      
      
      1. 
         

         Pharmacologic approach

         
         
         
         
         • 
           

           Abortive treatment

           
           
           
           
           1. 
              

              Oxygen

              
              
              
              
              • 
                

                8 L/min for 10 minutes or 100% by mask

              
              
           2. 
              

              Triptans

              
              
              
              
              • 
                

                Stimulation of 5-HT1 (serotonin) receptors produce vasoconstrictive effect and may abort attack

                
                
              • 
                

                Intranasal administration effective

              
              
           3. 
              

              Ergot alkaloids

              
              
              
              
              • 
                

                Stimulation of alpha receptors to cause vasoconstriction

                
                
              • 
                

                Most effective when given early in a cluster headache attack

                
                
              • 
                

                Intranasal administration is effective

           
           
         • 
           

           Preventive/prophylactic treatment

           
           
           
           
           1. 
              

              Calcium channel blockers

              
              
              
              
              • 
                

                Verapamil considered most effective

                
                
              • 
                

                Can be combined with ergotamine and lithium

              
              
           2. 
              

              Anticonvulsant

              
              
              
              
              1. 
                 

                 Topiramate and divalproex found to be most effective for prophylaxis

                 
                 
              2. 
                 

                 Mechanism of action is unclear

         
         
      2. 
         

         Surgical approach

         
         
         
         
         • 
           

           Percutaneous radiofrequency ablation of the gasserian ganglion

           
           
           
           
           1. 
              

              50% success rate

              
              
           2. 
              

              20% have fair-to-good results

              
              
           3. 
              

              30% failure rate

           
           
         • 
           

           Gamma knife radiosurgery

           
           
           
           
           1. 
              

              Increased risk for disturbance in facial sensation

           
           
         • 
           

           Occipital nerve block

           
           
           
           
           1. 
              

              Abortive procedure for cluster headache

           
           
         • 
           

           Deep brain stimulation (DBS)

           
           
           
           
           1. 
              

              Electrodes placed in ipsilateral posterior inferior hypothalamus.

              
              
           2. 
              

              Candidates for DBS are those patients who have chronic cluster headaches refractory to pharmacologic therapy.

           
           
         • 
           

           Stimulation of the pterygopalatine ganglion

           
           
           
           
           1. 
              

              Candidate for stimulation are selected patients with chronic cluster headaches.

Facial Pain

1. 
   

   Trigeminal neuralgia

   
   
   
   
   1. 
      

      Characteristics

      
      
      
      
      1. 
         

         Distinct, sudden, lancinating pain following the sensory distribution of the trigeminal nerve

         
         
      2. 
         

         Pain is most similar to an “electric shock” that worsens in less than 20 seconds and begins to fade to burning

         
         
         
         
         • 
           

           Pain shoots from the corner of the mouth to the angle of the jaw in 60%.

           
           
         • 
           

           Pain shoots from the upper lip or teeth to the eyebrow or area around the eye in 30%.

           
           
         • 
           

           V1 involved in less than 5% of cases.

           
           
         • 
           

           V2 and V3 distribution affected in 35% of patients.

         
         
      3. 
         

         Triggers: chewing, talking, smiling, drinking hot or cold fluids, touching, shaving, teeth cleaning, encountering cold air on the face

         
         
      4. 
         

         Common causes include vascular compression at the root entry zone or demyelination due to diseases like multiple sclerosis (MS)

      
      
   2. 
      

      Diagnosis

      
      
      
      
      1. 
         

         No laboratory, radiographic or electrophysiologic studies are routinely needed for patients with characteristic history and normal neurologic examination.

         
         
      2. 
         

         Criteria established by International Headache Society

         
         
         
         
         • 
           

           Paroxysmal attacks of pain that lasts up to 2 minutes and involves a distribution of the trigeminal nerves (V1-V3).

           
           
         • 
           

           Pain has at least one of the following characteristics: intense, sharp, superficial or stabbing, or pain starts from specific trigger areas or by triggering factors.

           
           
         • 
           

           Attacks are stereotyped in the individual patient.

           
           
         • 
           

           No neurologic deficit based on clinical examination.

           
           
         • 
           

           Pain is not attributed to another disorder.

      
      
   3. 
      

      Management

      
      
      
      
      1. 
         

         Multiple treatment options

         
         
         
         
         • 
           

           Pharmacologic therapy

           
           
           
           
           1. 
              

              75% of patients have substantial relief and adequate control with medical therapy.

              
              
           2. 
              

              Carbamazepine best studied and only indicated drug by FDA.

              
              
              
              
              • 
                

                Initial response to carbamazepine is diagnostic.

                
                
              • 
                

                Side effects: ataxia (15%), dizziness (44%), drowsiness (32%), nausea (29%), vomiting (18%).

              
              
           3. 
              

              Lamotrigine and baclofen are second-line options; gabapentin has been shown effective particularly with MS patients.

           
           
         • 
           

           Percutaneous glycerol or thermal rhizotomy of the gasserian ganglion

           
           
         • 
           

           Balloon compression

           
           
         • 
           

           Open cranial procedures (ie, microvascular decompression)

           
           
           
           
           1. 
              

              Most durable treatment

           
           
         • 
           

           Radiation therapy (ie, gamma knife radiosurgery)

   
   
2. 
   

   Cranial neuropathy syndromes

   
   
   
   
   1. 
      

      Tolosa-Hunt syndrome

      
      
      
      
      1. 
         

         Episodic unilateral orbital or retro-orbital pain with opthalmoplegia

         
         
      2. 
         

         Involvement of cranial nerves (CN) III to VI

         
         
      3. 
         

         Thought to be due to a nonspecific granulomatous inflammation involving the posterior superior orbital fissure, orbital apex, and cavernous sinus

         
         
      4. 
         

         Diagnosis of exclusion (MRI needed to rule out other pathologies)

         
         
      5. 
         

         Symptoms last for average of 8 weeks if untreated

         
         
      6. 
         

         Treatment: steroids

      
      
   2. 
      

      Raeder syndrome

      
      
      
      
      1. 
         

         First division of trigeminal nerve involved causing neuropathic pain or sensory loss; other divisions of trigeminal nerve can also be involved

         
         
      2. 
         

         Sympathetic dysfunction also (miosis, ptosis) without anhidrosis

         
         
      3. 
         

         Neuroimaging necessary to exclude other diagnoses

         
         
      4. 
         

         Syndrome not specific to any underlying pathologic process

      
      
   3. 
      

      Gradenigo syndrome

      
      
      
      
      1. 
         

         Apical petrositis: infection of petrous temporal bone

         
         
      2. 
         

         Due to infection extending from middle ear and mastoid air cells into the pneumatized petrous apex via the perilabyrinthine air tract

         
         
      3. 
         

         Involvement of Dorello canal and possibly the trigeminal nerve

         
         
      4. 
         

         Abducens nerve palsy with possible orbital or retro-orbital pain

      
      
   4. 
      

      Vernet syndrome

      
      
      
      
      1. 
         

         Lesion (tumor, infection, fracture, thrombosis) of jugular foramen

         
         
      2. 
         

         CN IX to XI effected: ipsilateral trapezius and sternocleidomastoid weakness, dysphonia, dysphagia, loss of taste over posterior one-third of tongue, depressed pharyngeal sensation

      
      
   5. 
      

      Collet-Sicard Syndrome

      
      
      
      
      1. 
         

         Unilateral palsy of CN IX to XII

         
         
      2. 
         

         Lack of sympathetic dysfunction

   
   
3. 
   

   Stroke syndromes

   
   
   
   
   1. 
      

      Rule of thumb: acute neurologic deterioration with ipsilateral CN deficit(s) and contralateral sensory or motor dysfunction localizes the stroke to the brain stem (midbrain, pons, medulla)

      
      
   2. 
      

      Dejerine-Roussy syndrome

      
      
      
      
      1. 
         

         Stroke of the thalamus involving the (PCA)

         
         
      2. 
         

         Contralateral sensory loss, contralateral dysesthesia (thalamic pain), ballistic or choreoathetoid movements, transient hemiparesis

      
      
   3. 
      

      Weber syndrome

      
      
      
      
      1. 
         

         Stroke of the caudal midbrain involving the posterior cerebral artery (PCA)

         
         
      2. 
         

         Ipsilateral gaze weakness (oculomotor nerve palsy), contralateral weakness

      
      
   4. 
      

      Benedikt syndrome

      
      
      
      
      1. 
         

         Stroke of the tegmentum (midbrain floor) involving the PCA

         
         
      2. 
         

         Oculomotor nerve palsy, contralateral hemichorea, hemiathetosis (red nucleus damage)

      
      
   5. 
      

      Raymond syndrome

      
      
      
      
      1. 
         

         Stroke of the pons involving the paramedian branches of the basilar artery

         
         
      2. 
         

         Ipsilateral lateral gaze weakness, contralateral weakness

      
      
   6. 
      

      Foville syndrome

      
      
      
      
      1. 
         

         Stroke of inferior medial pons involving the basilar artery

         
         
      2. 
         

         Contralateral hemiparesis, ipsilateral facial palsy (CN VII), lateral gaze palsy (CN VI), reduced touch and position sense (medial lemniscus)

      
      
   7. 
      

      Millard Gubler syndrome

      
      
      
      
      1. 
         

         Stroke of the basis pontis (caudal pons) involving the basilar artery

         
         
      2. 
         

         Contralateral weakness, ipsilateral lateral gaze weakness, ipsilateral facial weakness

      
      
   8. 
      

      Palatopharyngeal paralysis of Avellis

      
      
      
      
      1. 
         

         Stroke of cephalad portion of nucleus ambiguous

         
         
      2. 
         

         Paralysis of the palatal, pharyngeal muscles with sparing of laryngeal muscles

         
         
      3. 
         

         Somatotopic organization of motor nucleus places laryngeal muscles caudal

      
      
   9. 
      

      Dejerine’s anterior bulbar syndrome

      
      
      
      
      1. 
         

         Stroke of paramedian medulla involving the basilar artery

         
         
      2. 
         

         Sudden onset of reduced touch and position sense (dorsal column/medial lemniscus) of the contralateral side of body with contralateral hemiplegia, preservation of pain and temperature, with ipsilateral tongue weakness (CN XII) and upbeat nystagmus, without facial droop

      
      
   10. 
       

       Wallenberg syndrome

       
       
       
       
       1. 
          

          Stroke of lateral medulla involving the vertebral artery

          
          
       2. 
          

          Ipsilateral loss of facial sensation, ataxia, nystagmus/vertigo/nausea (vestibular nucleus involvement), dysphagia (nucleus ambiguous), Horner syndrome, contralateral hemisensory loss (spinothalamic tract)

   
   
4. 
   

   Seizure disorders

   
   
   
   
   1. 
      

      Infantile spasms (West syndrome)

      
      
      
      
      1. 
         

         Sudden flexor or extensor spasms of head, trunk, or limbs

         
         
      2. 
         

         Associated with tuberous sclerosis (neurocutaneous syndrome)

         
         
      3. 
         

         On EEG, see hypsarrhythmia

      
      
   2. 
      

      Juvenile myoclonic epilepsy

      
      
      
      
      1. 
         

         Myoclonic jerks that arise usually in the morning

         
         
      2. 
         

         Patients have normal intelligence

         
         
      3. 
         

         On EEG, see 4- to 6-Hz spike waves and polyspike discharges

      
      
   3. 
      

      Benign focal epilepsy of childhood

      
      
      
      
      1. 
         

         Generalized seizures at night, focal seizures during the day

         
         
      2. 
         

         On EEG, see di- or triphasic sharp waves

      
      
   4. 
      

      Petit mal

      
      
      
      
      1. 
         

         Frequent, blank staring spells

         
         
      2. 
         

         On EEG see generalized, symmetric 3-Hz spike-wave discharge

      
      
   5. 
      

      Gelastic seizures

      
      
      
      
      1. 
         

         Involuntary laughter with alternating crying or sobbing spells; with precocious puberty when associated with hypothalamic hamartoma

         
         
      2. 
         

         25% associated with hypothalamic hamartoma

         
         
      3. 
         

         21% of patients with hypothalamic hamartoma have gelastic seizures

         
         
      4. 
         

         Hypothalamic hamartoma associated with other midline deformities (ie, callosal agenesis)

      
      
   6. 
      

      Temporal lobe seizures

      
      
      
      
      1. 
         

         Most common in adults

         
         
      2. 
         

         Involves mesial temporal structures

         
         
      3. 
         

         Associated with auras (hallucinations, sensory illusions, viscerosensory symptoms such as sensation over the abdomen or chest wall) and automatisms (stereotyped repetitive movement of the mouth, tongue, lips or jaw → lip smacking)

         
         
      4. 
         

         Anterior temporal lobe resection is 80% effective

         
         
      5. 
         

         On EEG, see focal temporal slowing or epileptiform sharp waves or spikes in the anterior temporal lobe region

   
   
5. 
   

   Inflammatory disorders of the nervous system

   
   
   
   
   1. 
      

      Multiple sclerosis (MS)

      
      
      
      
      1. 
         

         Acquired relapsing demyelinating disease that is disseminated throughout the central nervous system in time and space

         
         
      2. 
         

         Female predilection with peak presentation at 35 years of age

         
         
      3. 
         

         Optic neuritis or trigeminal neuralgia are common symptoms

         
         
      4. 
         

         Multiple patterns of presentation

         
         
         
         
         • 
           

           Relapsing-remitting: most common; occasional symptoms that resolve on their own

           
           
         • 
           

           Secondary progressive: begin as relapsing-remitting but then become progressively worse

           
           
         • 
           

           Primary progressive: symptoms do not relapse and become progressive

           
           
         • 
           

           Progressive with relapses: symptoms that resolve but when they return are worse than the prior symptom

           
           
         • 
           

           Benign MS: patient with symptoms but remain functionally active for over 15 years

         
         
      5. 
         

         Radiographic signs

         
         
         
         
         1. 
            

            Dawson’s fingers: hyperintense lesions seen on MRI FLAIR sequence that are perpendicular to the ventricles

            
            
         2. 
            

            Open ring sing: enhancement is often incomplete on contrasted MRI studies

            
            
         3. 
            

            Lesions are often hyperintense on T2 MRI

         
         
      6. 
         

         Laboratory evaluation

         
         
         
         
         1. 
            

            IgG and albumin values from the serum and CSF should be measured in order to obtain the IgG index (a value greater than 0.7 is elevated).

            
            
         2. 
            

            Oligoclonal bands are often seen in CSF.

      
      
   2. 
      

      Amyotrophic lateral sclerosis

      
      
      
      
      1. 
         

         Disease of the upper and lower motor neurons

         
         
      2. 
         

         Signs of anterior horn cell disease without sensory neuropathy

         
         
      3. 
         

         Associated with Parkinson-like dementia complex

         
         
      4. 
         

         Most patients die within 5 years of symptom onset

      
      
   3. 
      

      Progressive multifocal leukoencephalopathy

      
      
      
      
      1. 
         

         Due to activation of JC virus (papovavirus) in immunocompromised patients

         
         
      2. 
         

         Reactivated virus attacks oligodendrocytes of subcortical white matter

         
         
      3. 
         

         Usually effects the parietal-occipital lobes

         
         
      4. 
         

         Seen in 4% of AIDS patients and patients with leukemia and lymphoma

         
         
      5. 
         

         MRI findings: hyperintense on T2 and FLAIR sequences, nonenhancing

         
         
      6. 
         

         Diagnosis confirmed by PCR analysis of JC virus RNA in CSF

      
      
   4. 
      

      Neuroborreliosis

      
      
      
      
      1. 
         

         Neurologic symptoms that arise after tick bite from Borrelia burgdorferi

         
         
      2. 
         

         Most common symptom is painful sensory radiculitis

         
         
      3. 
         

         Other symptoms are: Bell palsy, limb paresis, oculomotor weakness, arthralgias, cardiomyopathy

         
         
      4. 
         

         Treatment: penicillin or ceftriaxone

      
      
   5. 
      

      Meningitis

      
      
      
      
      1. 
         

         Bacterial meningitis

         
         
         
         
         • 
           

           Most common in the winter months

           
           
         • 
           

           Glucose decreased, protein elevated, CSF leukocytosis, and elevated opening pressure

         
         
      2. 
         

         Tuberculous meningitis

         
         
         
         
         • 
           

           Secondary to infection elsewhere, usually lungs

           
           
         • 
           

           Mortality rate higher than in bacterial meningitis

           
           
         • 
           

           Early treatment prevents poor outcome

           
           
         • 
           

           Involves skull base (basal meningitis)

           
           
         • 
           

           Treatment: isoniazid, rifampin, pyrazinamide, ethambutol

           
           
           
           
           1. 
              

              Treatment given for 18 to 24 months

              
              
           2. 
              

              INH depletes B6, therefore its use mandates replacement

           
           
         • 
           

           CSF profile: slight increase in intracranial pressure (ICP), pleocytosis with lymphocytic predominance, increased protein, decreased glucose

           
           
         • 
           

           CSF glucose should be normally 60% of serum glucose, usually 45 mg/dL or greater

         
         
      3. 
         

         Viral meningitis/encephalitis

         
         
         
         
         • 
           

           CSF profile: lymphocytic pleocytosis, mild elevation in protein, normal glucose.

           
           
         • 
           

           Peaks in the summer and fall seasons.

           
           
         • 
           

           RNA viruses: enteroviruses, arboviruses, rhabdoviruses, arenaviruses.

           
           
         • 
           

           DNA viruses: HSV-1, HSV-2, VZV, CMV, HHV-6.

           
           
         • 
           

           Enteroviruses are the most common cause of viral meningitis.

   
   
6. 
   

   Gertsmann syndrome

   
   
   
   
   1. 
      

      Syndrome due to lesion of dominant parietal lobe (inferior parietal lobule)

      
      
   2. 
      

      Acalculia, agraphia without alexia, right and left confusion, finger agnosia (inability to distinguish fingers of the hand)

      
      
   3. 
      

      Anosognosia (unawareness of the contralateral side of the body) involves the nondominant parietal lobe

   
   
7. 
   

   Central pontine myelinolysis

   
   
   
   
   1. 
      

      Due to aggressive correction of chronic hyponatremia

      
      
   2. 
      

      Symptoms: seizures, dysarthria, pseudobulbar palsy, dysphagia, hyperreflexia, quadriplegia, coma

      
      
      
      
      1. 
         

         Can also occur without symptoms

      
      
   3. 
      

      Diagnosis: confirm with MRI; CSF studies can show elevated myelin basic protein

      
      
   4. 
      

      In order to avoid this condition, correct sodium by 12 mmol/L in 24 hours

   
   
8. 
   

   Vitamin deficiency

   
   
   
   
   1. 
      

      Thiamine (B₁) deficiency

      
      
      
      
      1. 
         

         Wernicke encephalopathy

         
         
         
         
         • 
           

           Opthalmoplegia, nystagmus, anisocoria, gait ataxia, confusion, coma, death

         
         
      2. 
         

         Korsakoff psychosis

         
         
         
         
         • 
           

           Confabulation, psychosis, amnesia

           
           
         • 
           

           Mammillary bodies effected

         
         
      3. 
         

         With treatment symptoms of Wernicke involving the eyes improve; confusion improves to a varying degree; Korsakoff amnesia is left in about 80% of patients

      
      
   2. 
      

      B₁₂ deficiency

      
      
      
      
      1. 
         

         Subacute combined degeneration of the spinal cord

         
         
         
         
         • 
           

           Degeneration of posterior and lateral columns of the spinal cord

           
           
         • 
           

           Decreased pressure, vibration, and touch sense

           
           
         • 
           

           Weakness of the extremities, especially legs

           
           
         • 
           

           Ataxia

   
   
9. 
   

   Neurodegenerative diseases

   
   
   
   
   1. 
      

      Huntington disease

      
      
      
      
      1. 
         

         Trinucleotide repeat (CAG) localized on chromosome 4.

         
         
      2. 
         

         Autosomal dominant disease with complete penetrance.

         
         
      3. 
         

         More common in males with symptoms beginning at age 35 to 40.

         
         
      4. 
         

         Abnormal gene products cause damage to inhibitory pathway between motor cortex and subcortical structures causing hyperkinesia and choreoathetosis.

         
         
      5. 
         

         Disease progresses to death within 20 years of symptom onset.

      
      
   2. 
      

      Friedreich ataxia

      
      
      
      
      1. 
         

         Trinucleotide repeat (GAA) located on chromosome 9.

         
         
      2. 
         

         Frataxin gene not expressed in this disease; frataxin is an iron storage protein that is not expressed.

         
         
      3. 
         

         Symptoms related to degeneration of spinal cord tracts, medulla, and deep nuclei → ataxia, dysarthria, areflexia.

         
         
      4. 
         

         Symptoms begin between 10 and 15 years and disorder is deadly by middle age (40-50).

      
      
   3. 
      

      Alzheimer disease

      
      
      
      
      1. 
         

         A type of dementia associated with language dysfunction, intellectual loss, and memory loss.

         
         
      2. 
         

         Can be a rare cause of new onset auditory hallucinations.

         
         
      3. 
         

         Diagnosis based on history, physical examination, and brain imaging so as to exclude reversible causes of dementia.

         
         
      4. 
         

         Several genes associated with AD → the E4 allele of the apolipoprotein E (chromosome 19) is associated with 25% to 40% of all cases.

         
         
      5. 
         

         Degeneration of the nucleus basalis of Meynert causes decreased cholinergic input to frontal cortex.

         
         
      6. 
         

         Treatment: Tacrine (central acting acetylcholinesterase inhibitor) and donepezil (reversible acetylcholinesterase inhibitor) may slow cognitive decline.

   
   
10. 
    

    Brain stem auditory evoked response (BAER)

    
    
    
    
    1. 
       

       Can be measured from several important components of the auditory pathway.

       
       
    2. 
       

       Seven peaks in BAER:

       
       
       
       
       1. 
          

          Wave 1: auditory nerve

          
          
       2. 
          

          Wave 2: cochlear nucleus

          
          
       3. 
          

          Wave 3: superior olive

          
          
       4. 
          

          Wave 4: lateral lemniscus

          
          
       5. 
          

          Wave 5: inferior colliculus

          
          
       6. 
          

          Wave 6: medial geniculate body

          
          
       7. 
          

          Wave 7: auditory radiations/cortex

       
       
    3. 
       

       BAER shows prolonged latency with structural lesion of the brain stem or auditory nerve.

       
       
    4. 
       

       BAER is abnormal in 90% of patients with acoustic schwannoma and usually consists of delayed conduction from the auditory nerve to the caudal pons (waves 1-3).

       
       
    5. 
       

       BAER is abnormal in 33% of MS patients and usually involves increased latency between waves 3 and 5.