Cognitive function in the locked-in syndrome.
OBJECTIVE
The lockedin syndrome (LIS) originates from a ventro-pontine lesion resulting in a complete quadraplegia and anarthria. Classically, communication remains possible by means of spared vertical eye movements and/or blinking. To allow assessing cognitive functions in LIS patients, we propose here a neuropsychological testing based on eye-coded communication.


METHODS
Ten chronic LIS survivors were assessed 1 to 6 years after their brain insult. One patient was evaluated subacutely (at 2 months) and retested at 6 and 16 months. Neuropsychological testing encompassed short- and long-term memory, attention, executive functioning, phonological and semantic processing and verbal intelligence.


RESULTS
None of the patients showed alterations in verbal intelligence. Impairments in one or several tests were found in five patients. In three of these patients, neuropsychological deficits could be related to additional cortical or thalamic structural brain lesions. In the other 2 patients, weakness or signs of fatigue only were observed in one or two cognitive tasks. Repeated measures in a subacute patient with pure brainstem lesion indicate the recovery of good levels of cognition 6 months after injury.


CONCLUSIONS
Results indicate that LIS patients can recover intact cognitive levels in cases of pure brainstem lesions, and that additional brain injuries are most likely responsible for associated cognitive deficits in the LIS. Furthermore, a systematic neuropsychological assessment in LIS patients would allow detecting their cognitive deficits,which will contribute to improve their quality of life and of communication with family and medical caretakers.
Schnakers
Caroline
C
Cyclotron Research Center, University of Liège, Belgium. C.Schnakers@student.ulg.ac.be
Majerus
Steve
S
Goldman
Serge
S
Boly
Melanie
M
Van Eeckhout
Philippe
P
Gay
Stephane
S
Pellas
Frederic
F
Bartsch
Valerie
V
Peigneux
Philippe
P
Moonen
Gustave
G
Laureys
Steven
S
D000328:Adult; D001288:Attention / Q000502:physiology; D001930:Brain Injuries / Q000523:psychology; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology; D007802:Language; D008297:Male; D008568:Memory / Q000502:physiology; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D011782:Quadriplegia / Q000523:psychology*; D012016:Reference Values; D015203:Reproducibility of Results; D014705:Verbal Behavior / Q000502:physiology