kleine - levin syndrome ( kls ) named by critchley and hoffman after klein and levin who described the disorder first , is a sleep - related disorder , the exact cause of which is not established . this is because of the observation that symptoms are often preceded by infectious diseases like influenza . there is also the association between kls and hla ( human leukocyte antigen)-dqb1 * 0201 which supports the autoimmune etiology . factors believed to act as precipitators of illness include infections , sleep - deprivation , trauma , alcohol consumption , among others . it typically affects adolescent males and though it has a recurring - remitting course , it is generally believed to be a benign condition that has a tendency to resolve spontaneously . there is also a proposed role for neurotransmitters like serotonin , dopamine , and orexin ( hypocretin ) . from available research , it is widely believed that a hypothalamic dysfunction is the core pathology in kls , in view of the characteristic alteration in sleep , appetite , and sexual behavior . kls is an intriguing disorder which appears to have several features overlapping with psychiatric disorders , especially bipolar disorder . there are a few cases reported from india , some highlighting the occurrence of psychiatric symptoms during illness . a 20-year - old , right - handed , xi standard educated male was admitted at the psychiatry ward with complaints of abnormal behaviour which had started approximately 20 days prior to admission . the complaints of the father were extreme irritability , abusive and aggressive behavior without provocation ; talking irrelevantly ; decreased sleep ; decreased self - care ; spitting excessively . on examination , he was found to be grandiose and disinhibited , and had delusions of reference and persecution predominantly against family members . he was found to be oriented to his surroundings at all times during ward stay . on detailed evaluation , he was found to have a history of periodic episodes of intense drowsiness and sleeping throughout the day . these episodes had been occurring since 2 years and lasted for variable periods of 10 to 20 days and subsided spontaneously . the episodes were separated by symptom - free periods of approximately 2 - 5 months . the father could not recall several key facts like any precipitating illness prior to onset of symptoms or when the latest such episode had occurred . during these episodes , there was no evidence of mood / behavioral changes suggesting depression / anxiety or any other major mental illness . there was history of nicotine dependence , but no other significant personal and family history was obtained . when he exhibited the presenting disturbed behavior , he was seen by a private psychiatrist who , after obtaining the above information diagnosed him as suffering from rapid - cycling bipolar disorder , and prescribed a combination of lithium and typical antipsychotic medication and advised admission . however , patient was uncooperative and noncompliant because of which he was brought to our outpatient department and then admitted in the ward . a provisional diagnosis of brief psychotic disorder in a case of kls was made , and patient was started on tablet olanzapine 10 mg in two divided doses which was gradually increased to 30 mg in three divided doses and later supplemented with haloperidol ( 20 mg in divided doses ) and trihexyphenidyl ( 8 mg in divided doses ) to achieve better behavior control . he was subjected to several investigations to rule out an organic basis of the presenting disturbances . routine investigations ( complete blood count , liver and renal function tests , fasting blood sugar , chest x - ray and electrocardiogram ) revealed only an elevated aspartate amino - transferase-138 iu / ml . cerebrospinal fluid ( chemistry , microscopy , and culture ) , thyroid function tests and antinuclear antibodies did not reveal any significant abnormality . the patient was discharged on 23 day after admission at which time he showed 100% improvement . after 3 months of onset of psychotic symptoms , patient is well - maintained and symptom - free . our patient was initially thought to be suffering from rapid - cycling bipolar disorder based upon the cyclical sleep disturbance . however , data from father and later from the patient himself did not reveal presence of any mood disturbances during the hypersomnolent periods . the facts that support our diagnosis include patient 's gender , age of onset of symptoms ( approximately 18 years ) , hypersomnia of cyclical nature with spontaneous remissions , and recurrences and lack of any symptoms in between episodes . the lack of hyperphagia and/or hypersexuality indicates that this was most likely an atypical form of kls . the patient could not be subjected to polysomnography evaluation as he was not experiencing the hypersomnolent episode at presentation . however , it might have revealed eeg changes like slowing of rhythm and reduced rapid eye movement ( rem ) sleep latency , among others during the periods of symptoms . these changes , however , are not found in all patients with kls and thus , can not be diagnostic . the occurrence of psychotic symptoms with kls has been recorded previously in case reports . however , whether there is any association between the two is still not determined as not all patients with kls go on to develop psychosis . the psychiatrist , who first evaluated our patient , diagnosed him as having rapid - cycling bipolar disorder . the hypersomnolent episodes may have be taken for recurrent atypical depressive episodes , several of which were followed by what was taken as a manic episode ( presenting symptoms ) . the issue is complicated by the well - known fact that depression which is recurrent and atypical is highly likely to be of bipolar nature . to add to this is the fact that treatment strategy for both conditions overlap significantly - lithium , stimulants , fluoxetine among others . psychotic symptoms have been described during the somnolent phases , though the patient 's history did not reveal so . it remains to be seen if the diagnosis of the patient holds up in the future , mainly as there is no definitive method available to us to establish it irrefutably . the development of newer techniques for diagnosis of kls would be a boon to these rare set of patients and definitely improve their management .
kleine - levin syndrome ( kls ) is a rare disorder of sleep diagnosed mainly on clinical grounds . 
 it presents a unique diagnostic dilemma for neurologists and psychiatrists ; especially due to a high risk of being diagnosed as a psychiatric condition like a mood disorder . however , there is literature available documenting the cooccurrence of psychiatric illnesses in patients diagnosed with kls . 
 the following case highlights the above points .