Abstract
Objective
Giant axonal neuropathy (GAN) is a progressive condition marked by abnormally large/dysfunctional axons. Childhood neurological symptoms (e.g., ataxia, loss of sensation, strength, and reflexes in limbs, and visual and hearing problems) eventually lead to central nervous system impairment (e.g., seizures, paralysis, and cognitive decline). The scant literature on cognition in GAN is mixed, with findings from no impairment all the way to dementia. We present a case of an adult GAN patient with milder symptoms.
Method
A 55-year-old Hispanic male with 13 years of education was referred from outpatient neurology for neuropsychological evaluation in a county hospital setting. He was symptomatic in childhood, but was not diagnosed with GAN until 2018. A comprehensive neuropsychological evaluation was conducted. His presentation was notable for anxious and restricted affect, rapid speech, and intense gaze. He appeared immature and at times guarded about his symptoms and history.
Results
Cognitive test results were valid and indicated normal-range IQ and generally intact cognitive abilities with mixed performances (and mild deficits) in visual memory and executive functioning. The MMPI-2-RF was invalid due to elevations on multiple validity scales, possibly due to limited insight and/or impression management (L-r highest).
Conclusions
The results add to the limited literature on cognition in GAN by describing a milder case. Our patient demonstrated some mixed cognitive difficulties as well as idiosyncrasies in personality that could reflect immaturity and/or reduced insight. In addition to further exploring its cognitive effects, future research into GAN should include the evaluation of personality and insight/metacognition in patients with milder symptoms.