Locked-in syndrome after central pontine myelinolysis, an outstanding outcome of two patients

Ann Clin Transl Neurol. 2024 Mar;11(3):826-836. doi: 10.1002/acn3.51994. Epub 2024 Jan 23.

Abstract

Objective: Central pontine myelinolysis (CPM) is a rare demyelinating disease that affects the pons and which can cause extreme disabilities such as locked-in syndrome (LIS) in the initial phase. The aim of the study was to describe the evolution over a 12-month period of two patients with CPM causing an initial LIS.

Method: We retrospectively report the unexpected clinical outcome of these two patients in relation with the anatomical damages documented by brain MRI, associated with diffusion tensor imaging and reconstruction of corticospinal tracts in tractography. The following clinical parameters systematically assessed at 3, 6, 9, and 12 months: muscle testing on 12 key muscles (Medical Research Council), prehension metrics (box and block test and purdue pegboard), and independence for acts of daily living (functional independence measure).

Results: Both patients showed a progressive recovery beginning between 2 and 3 months after the onset of symptoms, leading to almost complete autonomy at 12 months (FIM > 110), with motor strength greater than 4/5 in all joint segments (MRC > 50/60). On brain MRI with tractography, CST appeared partially preserved at pons level.

Interpretation: The possibility of a near-complete functional recovery at 12 months is important to consider given the ethical issues at stake and the discussions about limiting care that may take place initially. It seems to be the consequence of reversible myelin damage combined with partially preserved neurons. Development of collateral pathways or resolution of conduction block may explain this recovery. MRI comprising DTI and tractography could play a key role in the prognosis of motor recovery.

Publication types

  • Case Reports

MeSH terms

  • Diffusion Tensor Imaging
  • Humans
  • Locked-In Syndrome*
  • Myelinolysis, Central Pontine* / diagnostic imaging
  • Myelinolysis, Central Pontine* / etiology
  • Pyramidal Tracts / diagnostic imaging
  • Retrospective Studies