Podiatric Surgeon s Primer on Thyroid Pathology and Entrapment Neuropathies Damien M. Dauphinee, DPM, FACFAS, CWS-P Past President Association of Extremity Nerve Surgeons
Goals and Objectives Is there a relationship? Discuss the evidence in the literature Recommend options for treatment
Thyroid Pathology Hypo and hyperthyroidism Associated with clinical and electrodiag. Myopathy Mono-neuropathy Poly-neuropathy
Thyroid Pathology Hypothyroidism Associated with clinical and electrodiag. Myopathy (10-80%) Mono-neuropathy (5-65%) Poly-neuropathy (9-72%) Somay G, et al. Neuromuscular status of thyroid diseases: A prospective clinical and electrodiagnostic study. Electrmyogr. Clin. Neurophysiol., 2007, 47, 67-78.
Hypothyroidism Carpal Tunnel Syndrome (CTS) Tarsal Tunnel Syndrome (TTS) Most common type of entrapment mononeuropathies Palumbo et al found 73% (31 hands) of 26 hypothyroid pts displayed symptoms of CTS, 16 pts (25 hands) in hyperthyroid pts had clinical symptoms of CTS. ALL SYMPTOMATIC PTS WERE EUTHYROID CTS remains common in thyroid pts even when they are euthyroid. Palumbo, CF, Szabo, RM, Olmsted, SL. et al. The effects of hypothyroidism and thyroid replacement on the development of carpal tunnel syndrome. J of Hand Surg. 2000:25: 734-739. Schwartz, MS, Mackworth-Young, GG, McKeron, R. The tarsal tunnel syndrome in hypothyroidism. J Neurol Neurosurg Psychiatry, 1975; 38: 241-247.
Thyroid Pathology Hypothyroidism Somay and colleagues looked at 40 cases of hypo (19 patients) and hyperthyroidism (21 patients) Control group was 29 healthy cases for upper extremities and 58 healthy cases for lower extremities. Somay G, et al. Neuromuscular status of thyroid diseases: A prospective clinical and electrodiagnostic study. Electrmyogr. Clin. Neurophysiol., 2007, 47, 67-78.
Thyroid Pathology Somay et al study Complete histories and full lab work up for all individuals. CBC, glucose, BUN, creatinine, B12 and folic acid, CPK, CPK-MB, GOT, GPT and LDH levels. Excluded known diabetics, renal failure, liver failure, malignancy, low serum B12 and folic acid levels, pts using drugs or alcohol which could effect the nervous system or thyroid hormone levels Somay G, et al. Neuromuscular status of thyroid diseases: A prospective clinical and electrodiagnostic study. Electrmyogr. Clin. Neurophysiol., 2007, 47, 67-78.
Thyroid Pathology Somay et al study Electrodiagnostic studies were performed. In the thyroid patients 30% showed evidence of entrapment mononeuropathy and diffuse peripheral neuropathy in 10%. 47% with hypothyroidism (38% with hyperthyroidism) showed electrophysiological abnormalities. Somay G, et al. Neuromuscular status of thyroid diseases: A prospective clinical and electrodiagnostic study. Electromyogr. Clin. Neurophysiol., 2007, 47, 67-78.
Treatment Options Kecechi and Degimenchi studied 40 patients over 18 y/o All showed lab values hypothyroidic Electrodiagnostic evidence of CTS in 15 patients and polyneuropathy in 7 patients. After thyroid replacement 35 pts were showing normal electrodiagnostic findings Authors recommending 3 months of replacement before considering surgical options. Kecechi, H, Degirmenci, Y. Hormone replacement therapy in hypothyroidism and nerve conduction study. Neurophysiol Clin. 2006; 36(2):79-83.
Entrapment Neuropathy and Hypothyroidism Ramadhan et al looked at the literature Hypothyroidism, nontraumatic common peroneal compression Reported a case of CPN entrapment syndrome in patient with thyroid hormone withdrawal in the presence of diabetes. Ramadhan A, Schondorf R, Tamilia M. Rhabdomyolysis and peroneal nerve compression associated with thyroid withdrawal in the setting of remnant ablation: review of the literature. Endocr Pract. 2011 Jul- Aug;17(4):629-35.
Duyff et al looked 45 pts 24 hypo and 21 hyperthyroid Newly diagnosed Excluded other causes of neuropathy like DM, alcoholism, liver and kidney dz, use of drugs known to cause neuropathy, malignancy, fam hx of neuropathy. Duyff RF, et al. Neuromuscular findings in thyroid dysfunction: a prospective clinical and electrodiagnostic study. J Neurol Neurosurg Psychiatry 2000;68:750-755.
Duyff et al looked 45 pts 33% of hypothyroid pts had residual symptoms and signs after 1 year of therapy. Prevalence of clinical and electrodiagnostically confirmed CTS was 25%. Duyff RF, et al. Neuromuscular findings in thyroid dysfunction: a prospective clinical and electrodiagnostic study. J Neurol Neurosurg Psychiatry 2000;68:750-755.
Etiology? Hypothesized that the mucinous material accummulations within the nerves and peripheral tissues accounts for the onset and progression of CTS and TTS. Schwartz, MS, Mackworth-Young, GG, McKeron, R. The tarsal tunnel syndrome in hypothyroidism. J Neurol Neurosurg Psychiatry, 1975; 38: 241-247.
Mononeuropathy in Hypothyroid Patient: now what? Ducic, Taylor and Dellon showed that neurolysis of the four medial nerve tunnels (tibial, medial calc, medial and lateral plantar). Improved pedal sensibility and balance 7% were hypothyroid patients Positive Tinel sign was an excellent predictor for which patients would benefit from surgery Ducic I, Taylor NS, Dellon AL. Relationship between peripheral nerve decompression and gain of pedal sensibility and balance in patients with peripheral neuropathy. Ann of Plast Surg. Feb;56(2):145-150, 2006.
Take Home Message When you see pts with thyroid disease Inquire about symptoms of peripheral nerve pathology Burning, tingling, lancinating pain (paresthesias) If they have been euthyroid for >3 months and continue to have symptoms and + Tinel Consider referring them to a peripheral nerve specialist