Category: Clinical Sciences/Health Conditions
A previously healthy 62-year-old man presented with three months of right foot drop, following several months of gradually increasing tripping over the right foot. He had just completed two months of PT with no improvement. He was using right AFO.
Examination revealed impaired right foot dorsiflexion (2/5), eversion (3/5), and great toe extension (2/5), with intact sensation. He exhibited steppage gait with increased right knee flexion during swing. Extensive neuropathy-specific laboratory testing was negative except for HIV-1 antibody/RNA suggestive of active HIV infection. EMG/NCS showed acute denervation of the right deep peroneal nerve and absent sensory evoked potential of the right superficial peroneal nerve. MRI RLE showed acute/subacute denervation changes in anterior compartment. MRI L-spine did not support radiculopathy.
Abacavir/doltegravir/lamivudine therapy was initiated. He restarted PT. At 6-month follow-up, his foot drop was completely resolved. No recurrence has been noted in subsequent visits over the next 18 months.
Peripheral neuropathy is a frequent complaint in patients with HIV. Mononeuritis multiplex is known to present early in the course of HIV infection, and can either resolve spontaneously or with antiretroviral treatment. Mononeuropathy is rare and classically described with cranial nerve involvement. We believe our patient experienced HIV-associated deep peroneal motor mononeuropathy leading to foot drop, which was the presenting sign of HIV infection. PT had no benefit until antiretroviral therapy was initiated, after which complete resolution of the foot drop was rapid.
This is the first known case of foot drop as the sole presenting sign of HIV infection, and dramatic and rapid resolution of the neurological deficit following initiation of antiretroviral treatment. While we cannot rule out a coincident spontaneous resolution, this case suggests that physiatrists should consider HIV in the differential diagnoses of acute foot drop, even if no signs or symptoms of systemic infection/AIDS exist.