Radiological Evaluation of Huntington’s Disease: A Case Report

Abstract

Huntington’s Disease (HD) is a rare neurodegenerative condition inherited in an autosomal dominant pattern, where Gamma Amino Butyric Acid-ergic (GABAergic) neurons in the basal ganglia progressively deteriorate. Symptoms include subcortical dementia, behavioural changes, midlife psychosis, and involuntary choreoathetosis movements. Imaging techniques like Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) show shrinkage of the caudate nucleus and putamen, alongside enlarged lateral ventricles. Diagnosis is confirmed through molecular analysis identifying the hallmark amplified Cytosine Adenine Guanine (CAG) triplet. The case report describes a 57-year-old female diagnosed with HD, presenting symptoms of accidental falls caused by involuntary jerky movements, along with behavioural changes and cognitive decline over three years. Initial Non Contrast Computed Tomography (NCCT) of the brain revealed bilateral basal ganglia and diffuse cerebral atrophy. Quantitative analysis indicated a decreased frontal horn width to intercaudate distance (FH/CC) ratio of 1.24 and an increased Intercaudate distance to inner table width (CC/IT) ratio of 0.30. Multivoxel Magnetic Resonance Spectroscopy (MRS) showed reduced N-Acetyl Alanine (NAA) and creatine (Cr) levels with an NAA/Cr ratio of 0.84. Magnetic Resonance Tractography and Diffusion Tensor Imaging (DTI) revealed elevated Fractional Anisotropy (FA) and diffusivity in the basal ganglia, and reduced FA with increased diffusivity in white matter tracts. Genetic analysis by Polymerase Chain Reaction (PCR) confirmed HD. Newer MRI like DTI allows early identification of disease and better assessment of disease progression and response to therapy. A multidisciplinary approach involving neurologists, psychiatrists, and other healthcare professionals is essential. Genetic counseling and psychosocial support are crucial for patients and their families. Early and accurate identification of HD is vital for timely interventions and improved symptom control.

Keywords

• adenine
• cytosine
• diffusion tensor imaging
• fractional anisotropy
• guanine