We present a comprehensive review of sleep studies performed in patients with brain lesions complemented by 16 additional personal selected cases and by discussion of the corresponding animal data. The reader is cautioned about the risk of establishing an erroneous correlation between abnormal sleep and a given disorder due to the important inter and intra variability of sleep parameters among individuals. Salient points are stressed: the high frequency of post-
stroke sleep breathing disorders is becoming increasingly recognised and may, in the near future, change the way this condition is managed. Meso-diencephalic bilateral
infarcts induce a variable degree of damage to both waking and non-REM sleep networks producing and abnormal waking and sometimes a stage 1
hypersomnia reduced by
modafinil or
bromocriptine, which can be considered as a syndrome of cathecholaminergic deficiency. Central pontine lesions induce REM and non-REM sleep
insomnia with bilateral lateral gaze
paralysis. Bulbar
stroke leads to frequent sleep breathing disorders. Polysomnography can help define the extent of involvement of various degenerative diseases. Fragmented sleep in
Parkinson's disease may be preceded by REM sleep behavioural disorders.
Multiple system atrophies are characterised by important sleep disorganization. Sleep waking disorganization and a specific ocular REM pattern are often seen in supra-nuclear ophtalmoplegia. In Alzheimer patients, sleep perturbations parallel the
mental deterioration and are possibly related to
cholinergic deficiency. Fronto-temporal
dementia may be associated with an important decrease in REM sleep. Few
narcoleptic syndromes are reported to be associated with a tumour of the third ventricle or a
multiple sclerosis or to follow a
brain trauma; all these cases raise the question whether this is a simple coincidence, a revelation of a latent
narcolepsy or, as in non-DR16/DQ5 patients, a genuine symptomatic
narcolepsy.
Trypanosomiasis and the abnormal
prion protein precociously after sleep patterns. Polysomnography is a precious tool for evaluating brain function provided it is realised under optimal conditions in stable patients and interpreted with caution. Several unpublished cases are presented: one case of pseudohypersomnia due to a bilateral thalamic
infarct and corrected by
modafinil, four probable late-onset autosomal recessive
cerebellar ataxias without sleep pattern anomalies, six cases of fronto-temporal
dementia with strong reduction in total sleep time and REMS percentage on the first polysomnographic night, one case of
periodic hypersomnia associated with a
Rathke's cleft cyst and four cases of suspected symptomatic
narcolepsy with a DR16-DQ5 haplotype, three of which were post-traumatic without MRI anomalies, and one associated with
multiple sclerosis exhibiting pontine hyper signals on MRI.