We report two patients who were repeatedly exposed to thallium poisoning experienced hair loss, polyneuropathy, and visual impairment. Nerve conduction studies (NCSs), visual evoked potentials (VEP), brainstem auditory evoked potentials (BAEP) changes, and optical neuropathy developed within a few months latency after the first subjective signs.
Thallium poisoning was confirmed by toxicological analysis of blood and/or urine and feces in both the patients and in the microscopic hair analysis of the daughter. Both patients were treated with Prussian blue.
The hair loss was fully reversible. During a 2-year follow-up after the poisoning, polpolyneuropathy in the lower extremities improved substantially.
Additionally, severe asymmetrical vision impairment persists in both women, with central scotomata and impaired color discrimination in both eyes. Substantial improvement of their visual function is unlikely.