Neurology

    Restless Leg Syndrome

    • Definition:
      • deep, ill-defined discomfort or dysesthesia usually involving the legs that occurs when a person is trying to fall asleep (i.e. crawling sensation).
      • Coupled with urge to move, and movement reduces or eliminates the sensation.
      • Typically occurs during middle age (rarely start in 20s).
      • Often familial, restless legs syndrome may worsen over time.
    • Treatment:
      • Dopamine agonists or opiates can alleviate symptoms.
      • Dopamine agonists
        • Pramipexole
        • Ropinirole

     

    Periodic Limb Movements

    • Recurrent, patterned leg jerks and tonic spasms that sometimes resemble a flexion reflex, usually occur every 20 seconds during early-stage sleep, and generally resolve deeper in the sleep cycle.
    • May disturb the sleeping partner and also awaken the patient
    • Leads to inadequate or fragmented sleep + daytime drowsiness.
    • Diagnosis:
      • Confirmed by polysomnography.
    • Workup
      • Check ferritin (can be ass'd w/ iron deficiency)
    • Treatment
      • Just like restless leg syndrome, can result from dopaminergic deficiency
      • Treated with dopamine agonists, such as pramipexole or ropinirole.

    Seizures

    Classification

    • Provoked?
      • Fever?
      • Metabolic? (Electrolytes, Glucose).
      • Trauma?
    • Unprovoked
      • Partial
        • Simple (no change in LOC)
          • Can be Motor, Sensory, Autonomic, Psychiatric
        • Complex (alteration of mood, memory, perception).
          • Can be dysphasic, dysmnesic (deja vu), cognitive (disoriented), affective (fear, anger), illusions, hallucinations.
      • Generalized
        • Tonic-clonic (Grand mal)
          • prodromal with unease, irritability.
          • Postictal: decreased LOC, flaccid limb/jaw, extensor plantar reflexes, loss of corneal reflex, headache, confusion, aching muscles, sore tongue, amneasia, elevated CK level. (lasting hours).
        • Absence (petit mal)
          • Usually only in children, unresponsive for 5-10s.  Sometimes eye blinging/rolling.
        • Tonic
          • Decreased LOC, muscle contraction in flexion or extension +/- drop attack, resp arrest.
        • Clonic
          • decreased LOC and repetitive clonic jerks.
        • Myoclonic
          • Brief contractions localized to muscle groups of one or more extremities.
        • Atonic
          • Loss of postural tone leading to fall.

     

    • Causes:
      • Epilepsy 30% (recent med changes? compliance?)
      • Vascular 15% (head trauma, CVA, acute VM)
      • Infection 10% (meningitis, abscess, sepsis, encephalitis)
      • Tumors 10%
      • Drug Overdose
        • INH toxicity
        • Antipsychotics
        • Sub/supratherapeutic levels of anticonvulsants.
        • Cyclosporine
        • B-Lactams.
        • Meperidine.
      • Other 35%
        • EtOH withdrawal
        • Benzos/barbiturates
        • Anoxia
        • Hypoglycemia
        • Electrolyte changes
        • Uremia
        • Liver failure
        • Body temp
        • Degenerative/Alzheimers disorders
        • Idiopathic

    Acute Treatment

    • Convulsive Seizure, treat as status epilepticus >2min
    • Step (in order, if does not terminate) Notes

      1. ABC

         Oral/nasal airway, 100% O2

      IV access, lateral decub, cardiac monitor

       
      1. D5W IV 50mL, Thiamine 100mg IV  

      2. Benzos (Pick ONE)
      - Lorazepam 2-4mg IV q5min - 2mg/min (Max dose 0.1mg/kg)

      - Diazepam 20mg IV sol'n PR, repeat x1 PRN

      - Midazolam 10mg IV sol'n IM/buccal/Intranasal, repeat x1PRN

      Watch for: sedation, resp depression, hypotension, arrhythmia (with lorazepam)

      3. Phenytoin

      - Load 20mg/kg IV at 50mg/min max rate

      - Maintenance: 100mg IV/PO q8h

      Longer onset (<1hr)

      - Mix phenytoin with normal saline (not dextrose, will precipitate).

      - Watch for hypotension, bradycardia, shock - slow down infusion.

      - Purple Hand Syndrome - extravasation of drug into tissue.  Switch IV site and monitor.

      4. Induction of Anesthesia - Call ICU, intubate

      NOTE:

      • In Pregnancy: Give MgSO4 4-6g IV load then 1-2g IV infusion.
      • In INH toxicity: 5g of pyridoxine IVenance: 100mg IV/PO q8hrs
       

     

    Prevention Treatments

    • Broad spectrum: (generalized from onset and partial onset seizures)
      • Felbamate
      • Lamotrigine
      • Levetiracetam
      • Refinamide
      • Topiramate
      • Valproate
      • Zonisamide
    • Narrow Spectrum (Simple partial, complex partial, and secondarily generalized)
      • Carbamazepine
      • Gabapentin
      • Lacosamide
      • Oxcarbazepine
      • Phenobarbital
      • Phenytoin
      • Pregabalin
      • Primidone
      • Tiagabine
      • Vigabatrin
    • Abscence seizures
      • Ethosuxiide

     

    • NO DRIVING until seizure-free for 6 months.

    Febrile Seizures (Pediatric)

    • Associated w fever, no evidence of intracrania infection
    • Age 6mo-6y
    • Tonic-clonic most common

    Simple vs Complex (Atypical)

    • Typical Features:
      • Generalized
      • Brief <15min
      • Once in 24hrs.

    Investigations

    • Lab tests (depends on hx)
    • Lumbar Puncture if:
      • <12mo old w/o fever source OR
      • if children with first complex febrile seizure

    Management

    • Seizure safety (Nothing in mouth, turn on side)
    • Treat infection
    • Treat fever (antipyretics - not effective in preventing seizure)
    • Prophylaxis not indicated.
    • Counselling:
      • Simple Febrile Seizure
        • Self-limiting seizure
        • Does not cause permanent brain damage
        • Increased risk of recurrence (30% if >12mo, and 50% if <12mo age)
      • Complex Febrile Seizure
        • Increased risk of epilepsy
        • Not increased risk of recurrence febrile seizures.

           

     

    Alzheimers Disease

    • Defined as progressive memory loss + one of:
      • 1. Aphasia (Difficulty w/ language)
      • 2. Apraxia (Difficulty with daily activities
      • 3. Agnosia (Difficulty recognizing objects)
      • 4. Executive Function (Difficulty planning, organizing, 

     

    Dermatomes & Myotomes

    Attached here

    Identifying Stroke On CT

    CT Stroke findings:

    1. Loss of grey-white differentiation (first sign... incredibly subtle)
      • ​Must also look at loss of differential lentiform nucleus and caudate.
      • Can use ASPECTS Score - prognostic indicators for acute stroke evaluation.  Basically "risk of bleeding from TPA"
        • If ASPECTS <7 too risky to use TPA
        • If ASPECTS >7 use TPA
    2. Hyperdense vessels.  I.e. "Dense MCA sign" or "dot sign".
    3. Patterns of Stroke
      • If anterior + posterior or bilateral (crossing vessel territories) --> likely cardioembolic. 
      • If unequal - favours one side, then check carotids.  
      • If new infarcts in the context of trauma ==> DISSECTION!!!! NEED CTA!
    4. Hemorrhagic findings.

     

    Trigeminal Neuralgia

    (Ref: AAFP: Trigeminal Neuralgia 2008; 77(9):1291-1296)

     

    • Vascular compression of the branch of trigeminal nerve.trigeminalDistribution.gif
      • Maxillary most common, opthalmic is least common
      • Right side of face is more common (1.5:1) - narrow foramen rotundum and ovale.
    • Pathophysiology: therory:
      • Demyelination of the nerve - prone to ectopic impulses transfered from light touch to pain fibres in close proximity (ephaptic conduction).
      • Demyelination thought to occur due to vascular compression of the nerve root by aberrant or tortuous vessels.  
      • Radiologic studies show close proximity of vessels to nerve (superior cerebellar artery) 

     

    • Symptoms/Diagnosis:
      • Clinical diagnosis:
        • Recurrent episodes of unilateral facial pain lasting only seconds but may recur infrequently or hundreds of times/day. (rarely during sleep).
        • Pain generally SEVERE, described as stabbing, sharp, shock-like, or superficial pain distributed in one or more trigeminal divisions.
        • Triggers: Talking, smiling, chewing, brushing teeth, shaving.
        • Uncommon and unusual in <40yo.
           
    • IHS Diagnostic criteria:
      • IHS Diagnostic Criteria

         

        CLASSICAL

           A. Paroxysmal attacks of pain lasting from fraction of second to two minutes, affecting one or more divisions of the trigeminal nerve and fulfilling criteria B or C

         

           B. Pain has at least one characteristic:

         

                      1.   Intense, sharp, superficial, or stabbing

                      2.   Precipitated from trigger zones or by trigger factors

         

           C. Attacks are stereotyped in the individual patient.

         

           D. There is no clinically evident neurologic deficit.

         

           E. Not attributed to another disorder.

         

        SYMPTOMATIC

         


         
    • Physical Exam: Rule out other conditions: mostly by physical exam.  There should be no new cranial nerve deficits.
    • Investigations:  MRI if atypical symptoms, abnormal exam, or age <40.
    • Treatment:
      • Medical Therapy:
        • Carbamazepine (Tegretol) studied extensively.
          • Meta-analysis: good evidence, NNT=2.5 NNH=3.7 (mild adverse events)
          • Can also be used as a diagnostic tool.
          • "Symptomatic" trigeminal neuralgia is less likely to respond.
          • Dosages: 100-2400mg per day.  Most respond to 200-800mg/day (divided BID or TID)
        • Second Line:
          • (Add or substitute if partial response or no response)
          • Baclofen (Lioresal) 10-80mg daily. (Good evidence)
          • Smaller trials shown benefit:
            • Phenytoin (Dilantin)
            • Iamotrigine 
            • Gabapentin
            • Topiramate
            • Clonazepam
            • Pimozide
            • Valproic Acid
        • Others:
          • Lidocaine, Capsaicin (topical), IM sumatriptan, intranasal lidocaine, acupuncture, dextromethorphan. 
      • Surgical
    1. Percutaneous: Glycerol injection, balloon compression, radiofrequency, gamma knife.
    • Less effective than invasive, higher incidence of sensory loss.
    1. Invasive: Trigeminal rhizotomy and microvascular decompression.
    • Risks: stroke, meningitis, death (2%)
    • Longest relief at 10 years in >70% of patients.
    • Low risk of symptom recurrence and sensory loss.

     

    Nystagmus

    • Generally classified into neuropathologic and non-neuropathologic
    • Differential: 
      • Ocular Disease
      • Drug effects
      • Peripheral vestibular disease
      • CNS Disease
    • Classified in many ways, but one of the ways is:
      • Pendular (Both phases equal amplitude and velocity)
        • Rarely neurologic disease
      • Jerk (fast phase and slow phase)
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