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

Roberto Ceravolo,Daniela Frosini,Eleonora Del Prete,Gabriele Siciliano,Gabriele Bellini,Elisa Unti

doi:10.1186/s12883-021-02345-y

Roberto Ceravolo, Daniela Frosini + Show 4 more

Open Access

https://doi.org/10.1186/s12883-021-02345-y

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Journal: BMC Neurology	Publication Date: Aug 25, 2021
Citations: 5	License type: open-access

Affiliation: University of Pisa

Abstract

BackgroundSpastic Paraplegia type 7 (SPG7) is one of the most common autosomal recessive Hereditary Spastic Paraplegias (HSP); Spastic Paraplegias (SPGs) can present as hereditary ataxias. However, ataxia is frequently the symptom of presentation of many other hereditary/sporadic disorders, such as Multiple system atrophy type C (MSA-C), an α-synuclein sporadic neurodegenerative disorder, in which cerebellar ataxia is one of the main clinical features. Dopamine Transporter imaging (DAT-SCAN), associated with clinical features, can be a helpful tool in order to distinguish MSA-C from other causes of ataxia.Case-presentationWe present the case of a 70-year-old man with gait difficulties over a period of 3 years and frequent backward/lateral falls. He also reported urinary urge incontinence, but no symptoms that are compatible with orthostatic hypotension. On neurological examination he showed ataxic gait, spasticity in the left lower limb and trunk and limb ataxia, especially on the left side. Mild hypokinesia was found in all 4 limbs, especially in the left foot. MRI revealed atrophy of the cerebellar hemispheres and vermis. DAT-SCAN imaging revealed bilateral nigro-striatal degeneration, which was compatible with a diagnosis of possible MSA-C. Considering the atypical disease course (the patient walked without any support after 3 years), we carried out a genetic investigation for Ataxia, and a mutation in SPG7 was found.ConclusionsDAT-SCAN imaging, evaluated together with the clinical findings, can be useful for differentiating MSA from other possible causes of adult-onset Ataxia. Indeed, patients with MSA-C generally show a decreased uptake of dopamine transporters in DAT-SCAN imaging. Ours is the first case reported in the literature of a patient with SPG7 mutation with nigrostriatal degeneration and a clinical presentation of a possible MSA-C. Performing genetic investigations in patients with an atypical disease course is important to avoid MSA-mimicries.Identifying the correct diagnosis is important not only for prognostic reasons, but also for possible future genetic therapies.

Highlights

Spastic Paraplegia type 7 (SPG7) is one of the most common autosomal recessive Hereditary Spastic Paraplegias (HSP); Spastic Paraplegias (SPGs) can present as hereditary ataxias
Ours is the first case reported in the literature of a patient with SPG7 mutation with nigrostriatal degeneration and a clinical presentation of a possible Multiple system atrophy (MSA)-C
Among genetic forms of ataxia we can distinguish autosomal dominant forms, spinocerebellar ataxia (SCA), which is associated with trinucleotide repeat expansions in most cases; autosomal recessive forms, such as Friedreich Ataxia caused by intronic GAA repeat expansions of the FXN gene; sensory ataxic neuropathy, dysarthria and ophthalmoparesis syndrome (SANDO) caused by POLG mutations, Ataxia telangiectasia caused by ATM mutations or the Niemann-Pick disease type C caused by NPC1 or NPC2 mutations; X linked Ataxia, Bellini et al BMC Neurology (2021) 21:328 such as the fragile X tremor-ataxia syndrome caused by CGG repeat expansions within the FMR1 gene; Mitochondrial Ataxia, that includes Kearns-Sayre syndrome, myoclonic epilepsy with ragged red fibers (MERRF), mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) [2]

Summary

Conclusions

DAT-SCAN imaging, evaluated together with the clinical findings, can be useful for differentiating MSA from other possible causes of adult-onset Ataxia. Patients with MSA-C generally show a decreased uptake of dopamine transporters in DAT-SCAN imaging. Ours is the first case reported in the literature of a patient with SPG7 mutation with nigrostriatal degeneration and a clinical presentation of a possible MSA-C. Performing genetic investigations in patients with an atypical disease course is important to avoid MSA-mimicries. Identifying the correct diagnosis is important for prognostic reasons, and for possible future genetic therapies

Findings

Background

Discussion and conclusions