A 32 yo male presents with inability to extend at the R wrist occurring 7/4 and inability to extend at the L wrist 7/16
What is wrong?
Our patient had bilateral radial nerve palsy. When this happens on one side this is a classic case of “Saturday night palsy” where an intoxicated person sleeps with his/her arm in an awkward position compressing the radial nerve against a chair or other object usually at the medial humerus. The problem in this case is that it recurred on the opposite side several weeks later raising the possibility of a peripheral neuropathy .Peripheral neuropathies are the most common disorder of the peripheral nervous system in adults with a prevalence of 5-8%.
HOW IS A PATIENT EVALUATED FOR PERIPHERAL NEUROPATHY?
TYPES OF PERIPHERAL NEUROPATHY
Pressure palsies- This by definition is what causes a Saturday night palsy, pressure on the radial nerve. There is a hereditary neuropathy which makes it more likely to get pressure palsies. These are autosomal dominant and involve mutations in the PMP22 (peripheral myelin protein22) gene.
Metabolic neuropathies- Diabetes is the most common cause of peripheral neuropathy, Inherited abnormalities of cholesterol metabolism like Tangier disease ( random fact: they can be recognized because of fat deposition in the tonsils which cause them to be orange. )
tangier disease causes a peripheral neuropathy and presents with orange tonsils.
Chemotherapy- there is a prevalence of 19-85% with platinum=based antineoplastic agents, vinca alkaloids and taxanes causing the most damage.
Toxins- There is a 22-66% of neuropathy among chronic alcoholics. The higher numbers probably represent thiamine deficiency. Lead poisoning can present with a pure motor neuropathy. Glue sniffers often present with peripheral neuropathy.
Hexane, and cassava can cause peripheral neuropathies.
peripheral neuropathy caused by cassava in Nigeria
Immunologic neuropathies- CIDP Chronic demyelinating inflammatory polyneuropathy accounts for about 35% of peripheral neuropathies. Guillain barre is also classified as a peripheral neuropathy.
Bee stings can lead to demyelinating polyneuropathy especially in children.
Infection- HIV, strongyloides, Epstein Barr virus, hep B and C, leprosy and herpes can cause peripheral neuropathies.
Malignancy- Paraneoplastic syndromes can present with peripheral neuropathy. It has been reported in craniopharyngioma. POEMS(polyneuropathy , organomegaly, endocrinopathy, M protein and skin changes) has a monoclonal protein spike .
Our patient was admitted and tested for causes of peripheral neuropathies. He had CRP, esr, B12 , thiamine, RPR, HIV, hepatitis panel, CT and MR of the c spine, ana , lead level, and LP. All were neg as well as cryoglobulins, anca and testing for paroxysmal nocturnal hemoglobinuria. He never received his EMG but it is presumed he had a pressure palsy on both sides and he is receiving physical therapy.
Rust S, Rosler M, Funke H, et al Tangier disease is caused by mutations in the gene encoding ATP-binding caaawrrw renapoerwe 1. 1999. Nat Genet 22(4):352-5.
Zajaczkowska R, Kocol-Kepska M, Leppert W, et al. Mechanisms of chemotherapty-induced peripheral neuropathy. Int J Mol Sci. 2019 Mar;20(6):1451.
Netto A, Netto C, Mahadevan A, et al. Tropical ataxic neuropathy-a century old enigma. Neurol India. 2016 Nov-Dec 64(6):1151-1159.
