1 / 25

Neurology C ase P resentation August 31 st , 2012

Neurology C ase P resentation August 31 st , 2012. Dipika Aggarwal PGY 4 Neurology. Teen aged male admitted with acute onset generalized weakness for 1 day duration Woke up with diffuse weakness; no anti gravity strength in arms, unable to get out of bed

tracen
Download Presentation

Neurology C ase P resentation August 31 st , 2012

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Neurology Case PresentationAugust 31st, 2012 DipikaAggarwal PGY 4 Neurology

  2. Teen aged male admitted with acute onset generalized weakness for 1 day duration • Woke up with diffuse weakness; no anti gravity strength in arms, unable to get out of bed • Proximal > distal weakness; bilaterally symmetrical • Denied diplopia, dysphagia, dysarthria, facial droop, drooling or change in level of consciousness

  3. Denied any sensory complains • Denied trouble breathing, urinary or bowel incontinence • Denied any recent illness, trauma, travel or tick bite • One episode of non-bloody emesis prior to admission

  4. PMH: similar episode four months earlier, admitted to OSH for 4-5 days, ?? Diagnosed with GBS, ?? treated with plasmapheresis, no LP/ EMG • PSH: none • Home meds: None • FH: HTN, migraine, DM, asthma, no similar problem in family members • SH: denies smoking, ETOH or illicit drug use

  5. Physical exam • Vitals stable • General physical exam unremarkable • Neurological exam • Mental status: AAO * 4 • Speech : fluent with comprehension intact • CN 2-12: PERRLA, EOMI, normal facial sensation and symmetry, normal facial strength, hearing intact, equal palatal elevation and tongue midline

  6. Motor: Flaccid tone, motor strength 2/5 proximally and 3-4/5 distally BUE and BLE • DTRs: Areflexic , toes downgoing • Sensory: Intact to LT/PP/ Vibration and proprioception • Unable to test for cerebellar function and gait

  7. Where?? What??

  8. Labs • Hb - 14.6, WBC 6.1, Plt count 215 • Sodium 143, K 1.3, Chloride 110, BUN 13, Creatinine 0.83, Glucose 151, Calcium 9.3, Magnesium 2.0, Phosphorus 2.4 • CK 493, Aldolase 15.7 (on day 3) • TSH: 2.082, free T3 – 3.8, free T4 – 0.9 • Urine lytes: unremarkable

  9. Hospital course • Aggressive Potassium replacement • Started showing improvement in muscle strength on day 1 • By day 2 – strength was 5/5 BUE and BLE • Diagnosed with familial hypokalemic periodic paralysis • Discharged with follow up care with Jayhawk clinic

  10. Muscle channelopathies • Non dystrophic myotonias • Myotoniacongenita (CLCN1) • Paramyotoniacongenita (SCN4A) • Sodium channel myotonias (potassium aggravated myotonias) (SCN4A) • Periodic paralyses • Hypokalemic (CACNA1S/ SCN4A) • Hyperkalemic(SCN4A) • Anderson Tawil syndrome (KCNJ2)

  11. Periodic Paralysis Secondary • Hypokalemic: • Thyrotoxicperiodic paralysis • hyperaldosteronism • RTA • villous adenoma • cocaine binge • diuretics, licorice, steroids, ETOH • Hyperkalemic (k>7): • hyporenemichypoaldosteronism (DM/CRF) • oral K, CRF, chronic heparin, rhabdomyolysis • Normakalemic: • Guanidine, sleep paralysis, MG, TIA, conversion

  12. Hypokalemic periodic paralysis • HypoKPP1 and 2 - CACNA1S/ SCN4A gene • HypoKPP 1 is the most frequent form • 1 in 100,000 • Autosomal dominant inheritance pattern • M:F – 3 or 4:1 • Onset: first 2 decades of life

  13. Clinical features • Flaccid paralysis – mild focal weakness to severe generalized weakness • Occur anytime of the day; more common in morning • Absence of myotonia • Proximal > distal weakness; legs > arms • Sparing of facial, ventilatory and sphincter muscles • Lasts several hours to more than a day

  14. Frequency: highly variable • Frequency decreases after age 30; may become attack free in 40s and 50s • Permanent fixed weakness or slowly progressive weakness more common with HypoKPP1 • Attacks may be preceded by sensation of heaviness and or aching in the low back

  15. Precipitating factors • Strenuous physical activity followed by rest or sleep • High carb diet • ETOH consumption • Emotional stress • Concurrent viral illness • Lack of sleep • Medications like beta agonists, corticosteroids, and insulin

  16. Hypokalemic Periodic ParalysisGenetics • Mutations in voltage sensor segment D2S4 of 1 subunit of skeletal muscle Ca channel gene, chromosome 1q • Arg528His, Arg1239His, Arg1239Gly • Less commonly SCN4A mutation enhances Na inactivation

  17. Hypokalemic Periodic ParalysisPathophysiology • The mutation slows the activation rate of L-type Ca current to 30% of NL • Reduced RYR1-mediated Ca release from SER • Reduced calcium current density • Impaired E-C coupling • ? role of K and ? inexcitability • Ca homeostasis change reduces ATP-dependent K channel current and leads to abnormal depolarization (Tricarico D et al 1999)

  18. Diagnostic studies • Serum K < 3.0mEq/L • Serum CK level elevated • EKG changes – U waves, flattening of T waves • Provocative testing - Intravenous glucose load/ insulin • Electrophysiology • Sensory and motor NCS normal between attacks • During attacks – small CMAP. Reduced insertional activity, fibs and positive sharp waves • No myotonia on EMG • Short/ long exercise test

  19. Periodic ParalysisMuscle Pathology • Muscle biopsy reserved to atypical patients with normal provocative and gene testing • Vacuoles reflect permanent myopathy • Vacuoles represent proliferation, degeneration and autophagic destruction of T-tubules & SR • Large central vacuoles in hypokalemic PP

  20. Hypokalemic Periodic Paralysis

  21. Treatment • Reducing exposure to known triggers • Acute treatment – replacement of K • Acetazolamide – prevent attack recurrence and severity • Acetazolamide may ppt weakness in HypoKPP2 • Dichlorphenamide – no longer available • Triamterene and spironolactone

  22. Diagnosing Muscle Channelopathies • R/O secondary forms • Measure K+ during attack • Provocative testing for PP: seldom done! • Hypo: gluc/insulin • Hyper: K+ • Muscle Bx – vacuoles/dilated T-tubules • Electrophysiology • EMG • Short/long exercise tests • Genetics

  23. Electrophysiology: Short Exercise Test • More useful in MC • Baseline CMAP • Exercise 10 sec • Record CMAP immediately post exercise, then q 10 sec for 1 min. •  CMAP in MC and PMC • PMC exacerbated by cold • No change in CMAP in HypoKPP (Streib. Musc. Nerve. 1982; 5: 719-723) (Fournier. Ann. Neurol. 2004; 56: 650-661) (Fournier Neurology 2009)

  24. Long Exercise Test for Periodic Paralysis • Record ulnar CMAP Amp baseline • Exercise ADM 5 min • Check CMAP every 2 min. for 50 min • In PP (all types),  Amp immed post ex, over next 10-40 min, grad dec amp • In MC ↓ Amp immed post ex, rapid return to baseline • In PMC sustained ↓ Amp (McManis. Musc. Nerve. 1986; 9: 704-710) (Fournier. Ann. Neurol. 2004; 56: 650-661)

  25. References • Dr.Barohn’s presentation on “Muscle Channelopathies” • Anthony A.Amato and James A.Russell; Non dystrophic myotonias and periodic paralysis.Neuromuscular disorders 2008, McGraw Hill, Section II Chapter 29; 655-680 • Burge JA, Hanna MG. Novel insights into the pathomechanisms of skeletal muscle channelopathies;CurrNeurolNeurosci Rep. 2012 Feb Vol 12:62-69 • Hanna, Dipa L Raja Rayan and Michael G. Skeletal Muscle Channelopathies:Non Dystrophic Myotonias and Periodic Paralysis. Current Opinion in Neurology, 2010 Vol. 23: 466-476 • neuromuscular.wustl.edu • Doreen Fialho and Michael G.Hanna. Periodic paralysis, Handbook of Clinical Neurology, 2007 Vol. 86 (3rd series), p 89-90

More Related