HIV Associated Sensory Neuropathy

Background: In the era of highly active antiretroviral therapy, sensory neuropathies have increased in prevalence. We have documented the frequency and profile of the two most common forms of sensory neuropathies associated with Human Immunodeficiency Virus (HIV) infection and looked into clinicoelectrophysiological correlates to differentiate the two entities.

Methods: The study population comprised of all consecutive patients detected to be HIV positive and attending the Neurology outpatient department (from March 2011 to March 2012) who were aged ≥ 18 years and were able to give informed consent. The data were collected from the patient records (including CD4 counts and treatment details) and questionnaire based interview with each patient. All patients underwent detailed clinical examination and nerve conduction studies (NCSs).

Results: Among the total study population of 50 patients, there were 31 men and 19 women. Thirty two patients were in age range of 21 - 40 years and rest were above 40 years. 25 were on antiretroviral therapy (18 on regimen containing zidovudine; seven on regimen containing stavudine). The mean duration of antiretroviral therapy was 16.6±8.4 months. Low CD4 counts (<200) were noted in 24 patients (13 of these were on antiretroviral therapy). Clinically, the patients were classified as asymptomatic (n=34) and symptomatic (n=16). Among the symptomatic patients, nine were on antiretroviral therapy since less than one year (seven of these were on regimen containing stavudine). Ten patients aged more than 40-years had symptomatic neuropathy. No significant correlation was found between low CD4 counts and symptomatic neuropathy (p=0.21). Impaired vibration (100%) and absent ankle jerks (75%) were commoner than reduced pin sensitivity (46.6%). Twenty two patients had abnormal NCS results (18 of these were on antiretroviral therapy). Axonal distal symmetrical sensory neuropathy was the commonest pattern noted in 14 patients who were receiving antiretroviral therapy. Subclinical involvement as evidenced by abnormal NCSs was noted in 5 asymptomatic patients who were all on antiretroviral therapy.

Conclusion: Symptomatic neuropathy was seen predominantly in HIV patients who were on antiretroviral therapy. All patients receiving stavudine containing regimen had severe symptomatic neuropathy within 1 year. There was an increase in the likelihood of symptomatic neuropathy among patients aged > 40 years. Subclinical neuropathy was common in those on antiretroviral therapy. Axonal neuropathy was the commonest pattern noted in patients who were receiving antiretroviral therapy and demyelinating neuropathy in patients not on antiretroviral therapy. Surprisingly no significant correlation was found between low CD4 counts and symptomatic neuropathy.