Differential Diagnosis of Akinetic Mutism and Disorder of Consciousness Using Diffusion Tensor Tractography: A Case Report.

Dong Hyun Byun ,Sung Ho Jang

doi:10.3389/fnhum.2022.778347

Abstract

This paper presents a case in whom a differential diagnosis of akinetic mutism with a disorder of consciousness was made using diffusion tensor tractography (DTT). A 69-year-old female patient was diagnosed with subarachnoid hemorrhage, intraventricular hemorrhage, and intracerebral hemorrhage produced by the subarachnoid hemorrhage. She exhibited impaired consciousness with a Coma Recovery Scale-Revised score of 13 until 1 month after onset. Her impaired consciousness recovered slowly to a normal state according to the Coma Recovery Scale-Revised (23 points: full score) at 7 weeks after onset. On the other hand, she exhibited the typical clinical features of akinetic mutism (no spontaneous movement [akinesia] or speech [mutism]). On the DTT performed at 1-month, the upper, and lower dorsal ascending reticular activating systems, which are related to a disorder of consciousness, showed an almost normal state. In contrast, the prefronto-caudate and prefronto-thalamic tracts, which are related to akinetic mutism, showed severe injuries. These DTT results suggested that the patient's main clinical features were not a disorder of consciousness but akinetic mutism. Therefore, DTT for the ascending reticular activating system, and the prefronto-caudate and prefronto-thalamic tracts could provide additional evidence for a differential diagnosis of DOC and AM at the early stages of stroke.

Highlights

A differential diagnosis of akinetic mutism (AM) and disorder of consciousness (DOC) can be clinically difficult at the early stages of a brain injury
This study hypothesized that reconstruction of the neural tracts related to AM and DOC using diffusion tensor tractography (DTT) could be useful in a differential diagnosis of AM and DOC
None of the prefronto-thalamic tracts were reconstructed except for the right ventrolateral and left dorsolateral tracts, which showed severe thinning (Figures 1E,F). This patient showed a DOC until she was admitted to the rehabilitation department 1 month after onset. She revealed the typical clinical features of AM when her consciousness had recovered to a normal state 7 weeks after onset (Marin and Wilkosz, 2005)

Summary

INTRODUCTION

A differential diagnosis of akinetic mutism (AM) and disorder of consciousness (DOC) can be clinically difficult at the early stages of a brain injury. Brain magnetic resonance images taken 1 month after onset revealed leukomalactic lesions in both basal forebrains (Figure 1A) Her impaired consciousness recovered slowly to a normal state as Coma Recovery Scale-Revised (23 points) (auditory function, 4 [consistent movement to commend]; visual function, 5 [object recognition]; motor function, 6 [functional object use]; verbal function, 3 [intelligible verbalization]; communication, 3 [oriented]; and arousal, and 3 [attention) at 7 weeks after onset (Giacino et al, 2004). She showed no spontaneous movement or speech and remained in a lying position all day with no spontaneous activity. None of the prefronto-thalamic tracts were reconstructed except for the right ventrolateral and left dorsolateral tracts, which showed severe thinning (Figures 1E,F)

DISCUSSION

ETHICS STATEMENT