Human brain pathology in myotonic dystrophy type 1: A systematic review

Area of Science:

• Neuropathology
• Neuroscience
• Genetic disorders

Background:

• Myotonic dystrophy type 1 (DM1) presents with varied cognitive, behavioral, and affective symptoms.
• Brain imaging in DM1 reveals widespread grey and white matter abnormalities.

Purpose of the Study:

• To systematically review the existing literature on microscopic brain pathology in DM1 patients.
• To categorize and discuss neuropathological findings in relation to anatomical regions and anomaly types.

Main Methods:

• Conducted a structured literature search in EMBASE and MEDLINE databases.
• Included full-text studies reporting on microscopic brain pathology in DM1 patients without confounding comorbidities.
• Analyzed findings based on anatomical location and nature of observed anomalies.

Main Results:

• Identified three main categories of neuropathological findings: protein/nucleotide deposits, neuronal/glial cell changes, and white matter alterations.
• Observed that many findings are non-specific and can occur with normal aging.
• Noted similarities with Alzheimer's disease (neurofibrillary tangles) and cerebral small vessel disease (myelin loss, gliosis, dilated perivascular spaces), but without lacunar infarction or microbleeding.

Conclusions:

• The neuropathological findings in DM1 correlate with the disease's heterogeneous clinical and neuroimaging manifestations.
• Limitations include small study participant numbers, methodological constraints, and a lack of established links between histopathology and clinical/imaging data.