Positive DAT-SCAN in SPG7: a case report mimicking possible MSA-C

Area of Science:

• Neuroscience
• Genetics
• Neurology

Background:

• Spastic Paraplegia type 7 (SPG7) is a common autosomal recessive hereditary spastic paraplegia (HSP) that can present with ataxia.
• Ataxia is a common symptom in various neurodegenerative disorders, including Multiple System Atrophy type C (MSA-C), an α-synucleinopathy.
• Dopamine Transporter imaging (DAT-SCAN) aids in differentiating MSA-C from other causes of ataxia.

Observation:

• A 70-year-old man presented with a 3-year history of gait difficulties, falls, and urinary urge incontinence.
• Neurological examination revealed ataxic gait, spasticity, limb ataxia, and mild hypokinesia.
• MRI showed cerebellar atrophy, and DAT-SCAN indicated bilateral nigro-striatal degeneration, suggesting possible MSA-C.

Findings:

• A genetic investigation revealed a mutation in the SPG7 gene.
• This is the first reported case of an SPG7 mutation presenting with nigrostriatal degeneration and clinical features mimicking MSA-C.
• The patient's atypical disease course, with preserved ambulation, prompted genetic investigation.

Implications:

• DAT-SCAN combined with clinical findings is valuable for distinguishing MSA from other adult-onset ataxias.
• Genetic investigation is essential for patients with atypical presentations to avoid misdiagnosis of MSA mimics.
• Accurate diagnosis is critical for prognosis and eligibility for future genetic therapies.