Parsonage–Turner syndrome: A rare case of abacavir hypersensitivity reaction in HIV-infected patients

Neurologic Complications of Human Immunodeficiency Virus Infection

PURPOSE OF REVIEW

Widespread use of antiretroviral therapy (ART) has led to near-normal life expectancy in people with human immunodeficiency virus (HIV) infection. However, neurologic complications of HIV remain common; can affect any part of the neuraxis; and are due to direct effects of the virus, immunosuppression because of untreated HIV infection, aberrant immune responses in the setting of ART initiation, and ART toxicities.

RECENT FINDINGS

HIV-associated neurocognitive disorder (HAND) remains one of the most common neurologic complications of HIV encountered today, but milder forms predominate in people on ART. No specific treatments for HAND exist, but small trials and epidemiologic evidence suggest paroxetine, intranasal insulin, and maraviroc may have utility in its treatment; further trials of these agents are ongoing. Widespread ART use has decreased the incidence of central nervous system opportunistic infections, but prognosis often remains poor in those who develop opportunistic infections. High-titer positive serum cryptococcal antigen is strongly predictive of cryptococcal meningitis and provides a tool to enhance diagnosis in areas with limited resources. HIV is an independent risk factor for stroke, and accelerated aging associated with HIV infection results in neurologic diseases of older age occurring at much younger ages in individuals infected with HIV. Ongoing HIV replication in the CSF despite peripheral virologic suppression may contribute to the development of HAND and may not improve despite adjusting the ART regimen to increase central nervous system penetrance.

SUMMARY

Neurologists are likely to encounter patients infected with HIV in clinical practice. This article reviews the presentation, diagnosis, and management of the most common neurologic conditions associated with HIV infection and ART.

Acute lower motor neuron syndrome and spinal cord gray matter hyperintensities in HIV infection

Objective:

To describe a novel manifestation of lower motor neuron disease in patients with well-controlled HIV infection.

Methods:

A retrospective study was performed to identify HIV-positive individuals with acute, painful lower motor neuron diseases.

Results:

Six patients were identified with HIV and lower motor neuron disease. Two patients met the inclusion criteria of well-controlled, chronic HIV infection and an acute, painful, unilateral lower motor neuron paralytic syndrome affecting the distal portion of the upper limb. These patients had segmental T2-hyperintense lesions in the central gray matter of the cervical spinal cord on MRI. One patient stabilized and the second patient improved with immunomodulatory therapy.

Conclusions:

This newly described syndrome expands the clinical spectrum of lower motor neuron diseases in HIV.

Parsonage-Turner syndrome following post-exposure prophylaxis

BACKGROUND

The 'Parsonage-Turner syndrome' (PTS) is a rare but distinct disorder with an abrupt onset of shoulder pain, followed by weakness and atrophy of the upper extremity musculature, and a slow recovery requiring months to years. To our best knowledge, this is the first case describing symptoms and signs of PTS following the administration of a post-exposure prophylaxis (PEP) regimen against possible human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infection.

CASE PRESENTATION

A 25-year-old Caucasian man presented with pain and unilateral scapular winging following PEP against possible HIV and HBV infection. Although atrophy and weakness were observed for the right supraspinatus muscle, a full range of motion was achievable. Neurological examination, plain radiography of the right shoulder and electromyography showed no additional abnormalities. The patient was diagnosed with post-vaccination PTS and treated non-operatively. During the following 15 months the scapular winging receded and full muscle strength was regained.

CONCLUSION

Parsonage-Turner syndrome is a rare clinical diagnosis. The precise pathophysiological mechanism of PTS remains unclear, but it seems to involve an interaction between genetic predisposition, mechanical vulnerability and an autoimmune trigger. An immunological event, such as - in this case - a vaccination as part of PEP treatment, can trigger the onset of PTS. The clinical presentation is distinctive with acute severe pain followed by patchy paresis, atrophy and sensory symptoms that persist for months to years. No currently available tests can provide a definite confirmation or exclusion of PTS. Routine blood examination, electromyography (EMG), and computed tomography (CT) or magnetic resonance imaging (MRI) serve mainly to exclude other disorders. The recovery can be quite lengthy, non-operative treatment is the accepted practice. Supplementary administration of oral prednisolone could shorten the duration of pain. Although the outcome is typically preferable, a substantial amount of patients are left with some residual paresis and functional impairment.

Neuralgic amyotrophy (Parsonage-Turner syndrome)

Neuralgic amyotrophy (Parsonage-Turner syndrome or brachial plexus neuritis) is an uncommon syndrome whose cause is unknown. The suprascapular and axillary nerves and corresponding muscles are affected most frequently. The disorder exhibits a broad range of clinical manifestations, and patients frequently present to physicians of different subspecialties. Accurate diagnosis can be challenging and requires a thorough history and physical examination. Nerve conduction velocity and imaging studies assist in the evaluation. Treatment consists of symptomatic management. Symptoms can persist for more than than a year, but most patients note resolution of symptoms over time.