Neurolathyrism With Deep Vein Thrombosis and Bony Exostosis: Are They New Forms of Angiolathyrism and Osteolathyrism?

Lathyriasis or lathyrism is a form of upper motor neuron disease caused by the dietary intake of grass pea (Lathyrus sativus). It is an irreversible crippling disease with poor outcomes. The possible pathogenesis is attributed to a toxin present in the legume, i.e., BOAA (beta-n-oxalyl amino L-alanine). Lathyrism can also be associated with vascular involvement resulting in angiolathyrism, which is mediated by a toxin ß-aminopropionitrile, and bony involvement resulting in osteolathyrism characterized by bone growth impairment. A 12-year-old male child presented to us with chronic myalgia and a gradual decline in the power in the bilateral lower limbs, both in extension and flexion, followed by an inability to walk. On examination, he had spastic paraparesis with brisk deep tendon reflexes and positive Babinski sign with sustained bilateral ankle clonus suggestive of upper motor neuron lesion. Doppler studies of the bilateral lower limb suggested deep vein thrombosis of the right posterior tibial vein. His electrophysiological studies and neuroimaging were otherwise normal. We found deep vein thrombosis and bony exostosis, which have never been reported in the existing literature. This could be a new form of angiolathyrism and osteolathyrism we are reporting here. A review of dietary history revealed consumption of grass pea over the past few years daily, following which diagnosis of neurolathyrism was considered. A review of the literature does not suggest any specific treatment for this crippling disease and the treatment largely remains supportive. The child was provided vitamin C, gabapentin, and perampanel for neuromuscular pain, and low molecular weight heparin for deep vein thrombosis. Physiotherapy was initiated and surgical excision was planned by the orthopedic team for the exostotic lesion. The diagnosis of lathyrism should strongly be suspected if there is a history of consumption of grass pea. Public health education, improvement in the socio-economic condition, and strict prohibition of the sale and consumption of grass pea can root out the problem of lathyrism.