HPI CC: blurry vision Clinical Problem Solving Session Advances in Internal Medicine 2012 Discussant: Harry Hollander, MD Moderator: Nader Najafi, MD A 59 yo woman complained to her PMD of 3 months of intermittent blurry vision. At that time, an ophthalmologist noted no change in visual acuity and prescribed drops for dry eyes. About 3 weeks ago, she also noted decreased depth perception and double vision. These symptoms progressed to the point where she is now unable to drive HPI (cont.) She also noted several weeks of difficulty reaching for objects or arranging her hair scarf limited by weakness. She noted that it was difficult to rise from a chair or from bed secondary to weakness. She noted difficulty chewing food, without dysphagia or odynophagia. Pause for Discussion On ROS: reported mild new dyspnea on exertion without cough or chest pain. Reported dry eyes and dry mouth for several months. Loss of appetite led to a 7 lb wt loss over a few months. 1
H&P (cont.) PMHx: DM Hypertension Hyperlipidemia Menopause at age 51 Alopecia +ANA 1:160 centromere pattern in 2007 h/o cholecystectomy h/o uterine myomectomy (fibroids) H&P (cont.) Medications: ASA atenolol benazepril metformin atorvastatin insulin NPH and regular famotidine Allergies: none SHx/FHx Lives alone - used to work as administrative assistant, currently looking for job; no hx tobacco, EtOH, drugs. Father: metastatic colon ca, died in his 90s Mother: died in 80s, had CAD, glaucoma, UC/RA Aunt and 2 first cousins with SLE Pause for Discussion 2
Physical Exam Afebrile, BP 134/74, HR 100, RR 14, 97% on RA Gen: no acute distress Eyes: L>R ptosis, PERRL, EOM intact apart from R CN VI with slight delay and incomplete lateral gaze Visual acuity (with glasses): R 20/40, L 20/28 HEENT: Clear, dry oropharynx, neck without adenopathy, no thyromegaly no masses Pulm: CTAB CV: tachycardia, regular, no m/r/g Abd: +BS, non-tender, non-distended Physical Exam (cont.) Neuro: CN intact apart from CN VI Proximal muscle weakness at deltoids L (3+/5)>R (4-/5), and hip flexors bilaterally (4-/5). Otherwise strength 5/5 and sensation grossly intact. Mildly shuffling gait. No pronator drift. Difficulty rising from chair without using her arms Labs WBC 9.8 Hgb 13.2 Platelet 307 LFT s normal CK 163 ANA 1:640 ESR 15 CRP 1.1 Sodium 140 Potassium 5.0 Chloride 103 Bicarb 32 Creatinine 0.77 Calcium 10.5 Mg 1.4 Glucose 164 Pause for Discussion 3
Clinical Course: A referral to rheumatology for myositis was reviewed by the attending rheumatologist who instead recommended admission for expedited work-up. On exam she was noted to have 4/5 strength in her proximal UE b/l, she was unable to resist pressure on cheeks when puffed with air, unable to close eyes tightly and resist and unable to close jaw tightly, rapid finger movements intact. Clinical Course (cont.) CXR: Low lung volumes are noted bilaterally. No focal consolidations present. EKG: NSR at 92, no ischemic changes Her outpatient medications were continued, she was also written for magnesium sulfate repletion In the morning the new team evaluated the patient and consulted neurology. Neurology recommended measuring Vital Capacity, which was 650 ml & Negative Inspiratory Force, which was -70 cm H20 (ref. range -90 to - 120). The patient was transferred to the ICU for closer monitoring. Audience response A series of diagnostic tests were performed... 4
What is the most likely diagnosis? A. Statin myopathy B. Guillain-Barre, Miller-Fisher Syndrome C. Amyotrophic Lateral Sclerosis D. Lambert-Eaton Myasthenic Syndrome E. Myasthenia Gravis F. Lupus-related Vasculopathy G. Botulism 0% 31% 42% 11% 6% 6% 6% A. B. C. D. E. F. G. Answer Acetylcholine receptor Ab returned +16.8 on HD #3. An EMG with repetitive nerve stimulation was consistent with the final diagnosis: Myasthenia Gravis Discussion of Myasthenia Gravis Most common disorder of NMJ transmission Antibody-mediated attack on post-synaptic acetylcholine receptors or associated proteins Bimodal epidemiology: 2-3rd decades (female predominant) & 6-8th decades (male predominant) Fluctuating weakness; worse at the end of the day > 50% present with ocular sx of ptosis or diplopia 15% with bulbar sx of dysarthria, dysphagia, or fatigable chewing 5% with proximal limb weakness alone Discussion Respiratory muscle weakness can lead to respiratory failure: myasthenic crisis Sx progress and often peak months to years later; infection & medications can precipitate symptoms Diagnosis: bedside tests (Tensilon, ice pack), serologic testing (AChR Ab, MuSK Ab), and electrophysiologic (RNS or SF-EMG) Treatment: 1) symptom mgmt (anticholinesterase) 2) rapid immunomodulation, 3) chronic immunomodulation, 5
Hospital Course She was started on IVIG daily first dose on HD#2. CT chest was negative for thymoma. TSH returned at 2.4, RF negative Given her sicca sx, SSA and SSB were sent which returned negative After 48 hrs of observation in the ICU, she was transferred to the floor Hospital Course (cont.) Patient noted significant improvement in weakness, particularly with chewing, extra-ocular movements, diplopia, and dyspnea on exertion. After finishing course of IVIG, her extra-ocular movements had normalized, and her NIF and FVC were significantly improved from admission values. Following her course of IVIG, she was started on pyridostigmine for symptomatic relief, as well as mycophenolate. References Allan H. Ropper, Martin A. Samuels: Adams & Victor s Principles of Neurology, 9e. New York: McGraw-Hill Companies, 2009. Bird, Shawn, et al. Uptodate: Clinical Manifestations of Myasthenia Gravis. May 2012 <http://www.uptodate.com>. Stephen J. McPhee, Maxine A. Papadakis, Michael W. Rabow: CURRENT Medical Diagnosis and Treatment. New York: McGraw-Hill Companies, 2012. 6