Cryptogenic Sensory Polyneuropathy (CSPN) www.rrnmf.com Richard J. Barohn, MD Chair, Department of Neurology Gertrude and Dewey Ziegler Professor of Neurology University Distinguished Professor Vice Chancellor for Research University of Kansas Medical Center Kansas City, KS

Case 2 History 68 Male 3 year history slowly progressive numb / tingling toes, then feet, then to 6 cm above ankles Hot “burning” pain in feet Esp at night No symptoms in upper extremities No subjective weakness

Case 2 Physical Exam CN - NL Motor - Strength normal Extensor digitorum brevis Atrophy Sensory - Dec pin and touch to above ankles and distal fingers Timed vibration: great toe 2-3 sec distal fingers 18 sec Propriocep - NL Reflexes - 2+ arms 1+ knees Absent ankles Gait - Mildly poor Tandem

Answer: b. Symmetric distal sensory loss with or without weakness. Case 2 Question #1 What pattern of neuropathy does this patient have? Symmetric proximal and distal weakness with sensory loss (NP1) Symmetric distal sensory loss with or without weakness (NP2) Asymmetric distal weakness with sensory loss (NP3) Asymmetric proximal and distal weakness with sensory loss (NP4) Asymmetric distal weakness without sensory loss (NP5) Answer: b. Symmetric distal sensory loss with or without weakness.

Answer: c. 2-hour glucose tolerance test Case 2 Question #2 What laboratory tests should be ordered? Heavy metals screen in urine and blood Anti-Hu antibody 2-hour glucose tolerance test ESR Anti-sulfatide antibody Answer: c. 2-hour glucose tolerance test

Peripheral Neuropathy Work-up BLOOD TESTS DONE ON MOST PATIENTS REFERRED FOR NEUROPATHY CBC SMA-20 FBS BUN/Creat/LFTs SPEP and IFE B12 Glucose tolerance test/HgAlc

Case 2 NCS / EMG Motor NCS: Med / Uln - normal Per amp 0.5 mV / CV 37 m/sec Tib amp 2.0 mV / CV 37 m/sec Sen NCS: Med / Uln low amp / normal lat Sural – no response EMG - normal UE / LE except foot ABD HAL and gastroc: 2+ ABD HAL / 1+ fibs gastroc MUPs large/dec recruit Dx: Cryptogenic sensory polyneuropathy (CSPN)

Case 2 Question #3 What percent of patients with neuropathy seen at a tertiary care center ultimately are placed in the cryoptogenic/ idiopathic group? 10% 25% 50% 75% 90% Answer: b. 25%

Answer: e. All of the above Case 2 Question #4 What is a reasonable medication management approach for this patient? Amitriptyline Gabapentin Duloxetine Pregabalin All of the above Answer: e. All of the above

Pharmacologic Rx for Painful Neuropathy 3rd Line Bupropion SR Tiagabine Keppra Zonisamide Mexiletine Phenytoin 4th Line Opioids 1st Line Tricyclics Gabapentin Tramadol Duloxentine Pregabalin 2nd Line Carbamazepine Oxcarbazepine Lamotrigine Topiramate Venlafaxine XR Valproate

Pharmacologic Rx for Painful Neuropathy Topical Agents Over the Counter Capsaicin Salicyclate Menthol/Camphor By Prescription Lidocaine patch Lidocaine/Prilocaine Doxepin Diclofenac By Prescription – Compounding Pharmacies Ketroprofen/Amitiptyline/Tetracaine Ketroprofen/Cyclobenzaprine/Lidocaine Ketamine/Amitriptyline/Gabapentin Carbamazepine/Lidocaine Amitriptyline/Lioresal