www rrnmf com Cryptogenic Sensory Polyneuropathy CSPN Richard

www. rrnmf. com Cryptogenic Sensory Polyneuropathy (CSPN) 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

Case 2 Question #1 What pattern of neuropathy does this patient have? a) Symmetric proximal and distal weakness with sensory loss (NP 1) b) Symmetric distal sensory loss with or without weakness (NP 2) c) Asymmetric distal weakness with sensory loss (NP 3) d) Asymmetric proximal and distal weakness with sensory loss (NP 4) e) Asymmetric distal weakness without sensory loss (NP 5) Answer: b. Symmetric distal sensory loss with or without weakness.

Case 2 Question #2 What laboratory tests should be ordered? a) Heavy metals screen in urine and blood b) Anti-Hu antibody c) 2 -hour glucose tolerance test d) ESR e) 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 • B 12 • Glucose tolerance test/Hg. Alc

Case 2 NCS / EMG • Motor NCS: – Med / Uln - normal – Per amp 0. 5 m. V / CV 37 m/sec – Tib amp 2. 0 m. V / 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? a) 10% b) 25% c) 50% d) 75% e) 90% Answer: b. 25%

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

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

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