[A case of HTLV-1 associated myelopathy (HAM) with pseudopseudohypoparathyroidism]

We report a case of HTLV-1 associated myelopathy (HAM) with pseudopseudohypoparathyroidism (PPHP). A 57-year-old woman, without a history of blood transfusion, was admitted with numbness and pain in her legs. Pain sensation in both legs was reduced and tendon reflexes were exaggerated. She exhibited spastic gait. The diagnosis of HAM was made because of positive antibody for HTLV-1 in blood and CSF. She also had features of Albright syndrome (short stature, round face, and short fourth metatarsals) without abnormal calcium and phosphorus metabolism, leading to the diagnosis of PPHP. Brain CT revealed bilateral calcification of the basal ganglia. Although HAM rarely accompanies pseudohypoparathyroidism (PHP), there are few reported cases of HAM associated with PPHP. The exact mechanism of HAM is not known, but it is thought to involve an immune-related process. Since PHP is considered to induce a state of mild immunosuppression through reduction of 1,25-dihydroxyvitamin D3, it is possible that susceptibility to HAM could be augmented in the presence of PHP. If PPHP should be an incomplete form of PHP, a similar mechanism may be involved in the association of PPHP and HAM.