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the septum pellucidum is a thin membranous midline structure which separates the lateral ventricles in the brain .
cavum septum pellucidum ( csp ) is a condition characterized by the presence of a gap between the leaflets of the septum pellucidum .
this gap results from a failure of the leaflets to fuse during late fetal life and early infancy , as the hippocampus , amygdala , and other midline brain structures develop and grow .
cavum vergae ( cv ) comprises a posterior extension of csp , behind the anterior columns of the fornix and below the splenium of the corpus callosum .
although csp and cv may be present as a normal variation without clinically evident accompaniments or deficits , these have been considered as markers of impaired neurodevelopment . in this context
, csp has been associated with diverse neuropsychiatric syndromes including schizophrenia , bipolar disorder , alcoholism , antisocial behavior , or just susceptibility to psychosis .
csp with co - occurring cv is less common , but has been reported in developmental disorders , schizophrenia , late - onset catatonia necessitating electroconvulsive therapy , and treatment - resistant childhood - onset schizophrenia .
herein , we describe the incidental detection of cv in an elderly woman with schizophreniform psychosis .
we discuss the implications of the finding of csp with or without cv in such patients .
an 80-year - old woman was brought with a 1-month history of restlessness , repeated religious verbalizations , visual hallucinations , third person auditory hallucinations , religious shloka auditory hallucinations , delusions of reference and persecution , persistent irritability , and impaired sleep .
she performed competently on bedside tests of general information , attention , concentration , immediate memory , and recent memory .
a brain magnetic resonance imaging ( mri ) scan revealed an insignificant csp but prominent cv [ figure 1 ] .
t1-weighted magnetic resonance image showing cavum vergae ( arrow ) a provisional diagnosis of late - onset schizophreniform disorder ( diagnostic and statistical manual of mental disorders , fourth edition ) was made , and she was treated with quetiapine in a dose that was gradually uptitrated across 1 month to 200 mg / day .
she showed almost complete recovery after 4 - 6 weeks of treatment and has maintained improvement with quetiapine ( 150 mg / day ) at an 18-month follow - up .
as auditory hallucinations re - emerge if attempts are made to reduce the medication dose , the diagnosis has been revised from schizophreniform disorder to schizophrenia .
for example , takahashi et al . found the prevalence of a large csp ( > 5.6 mm ) was 9.3% in 162 first - episode psychosis patients , 11.2% in 89 chronic schizophrenia patients , 11.1% in 135 persons at ultra - high risk of psychosis , and 11.5% in 87 control subjects .
the length of the csp was also unassociated with the sulcal morphology of the anterior cingulate cortex .
therefore , questioned whether csp is a neurodevelopmental marker of psychosis and whether it really plays a major role in the neurobiology of psychosis . in this context , in a meta - analysis of 15 mri studies , trzesniak et al
. showed that relative to healthy controls ( n = 866 ) , csp was significantly associated with schizophrenia spectrum disorders ( n = 1054 ) only when it was large ( odds ratio 1.59 ; 95% confidence interval 1.07 - 2.38 ) .
a large csp , especially in association with cv , suggests abnormality of the septal nuclei as well as dysgenesis of midline forebrain structures such as the hippocampus and the corpus callosum . if a large csp or a csp with cv predispose to schizophrenia
, one might expect poor neuroadaptation from an early age , earlier onset of illness , and perhaps poor response to treatment , as well , in affected persons . in line with such a conjecture , liao et al .
he failed treatment with ziprasidone , aripiprazole , olanzapine , quetiapine , and clozapine , all of which had been prescribed in adequate doses .
interestingly , csp with cv has also been associated with late - onset psychotic symptoms , including late - onset catatonia .
one is that csp with or without cv is an incidental mri finding that has no bearing on psychopathology .
the other is that csp and cv increase the risk of major mental illness across the lifespan of the individual .
late onset , as sometimes reported , can be explained on the basis of compromised neuroadaptation exposed by age - related neurodegenerative changes .
these possibilities can be explored through mri studies in late - onset psychosis patients and matched healthy controls .
this is because csp and cv usually communicate and obliterate from posterior to anterior , during late fetal and early infant life ; that is , the cv obliterates first and the csp , afterward .
the presence of isolated cv may , therefore , indicate that midline neurodevelopment in early life did not occur in the expected sequence , or that there was a failure of development of isolated midline structures .
isolated cv has been described in relation to psychosis ; for example , wolf et al . reported a young adult with isolated cv associated with treatment - refractory schizophrenic illness .
there is otherwise little literature on the psychopathological significance of isolated cv , and our patient is probably the first case in the literature of late - onset schizophrenia with isolated cv . in a large study of 249 patients with neurodevelopmental
delay and 161 normal individuals , csp with or without cv discriminated between patient and control group whereas cv alone did not .
this seems to suggest that isolated cv may be an incidental finding that does not have neuropsychiatric implications .
importantly , however , this study did not examine elderly subjects nor did it examine subjects with psychosis ; the findings , therefore , neither support not refute the possibility that isolated cv , like csp with or without cv , is associated with a predisposition to psychosis , including psychosis of late - onset .
we present what may be the first case of isolated cv associated with late - onset schizophrenia .
effect relationship but that the relationship can not be considered confirmed ( as opposed to being coincidental ) without specific study .
cavum septum pellucidum ( csp ) and cavum vergae ( cv ) have separately and together been associated with an increased risk of neurodevelopmental disorders and psychosis ; however , there is little literature on the psychopathological significance of isolated cv , and no previous report of isolated cv in late - onset psychosis . 
 we describe an 80-year - old woman who presented with a 1-month history of psychotic symptoms qualifying for a diagnosis of schizophreniform disorder . 
 physical ( including neurological ) examination , bedside cognitive testing , and laboratory investigations were all within normal limits . a magnetic resonance imaging scan of the brain revealed an insignificant csp with prominent cv . 
 the patient showed almost complete recovery from psychosis after 4 - 6 weeks of treatment with quetiapine ( 200 mg / day ) . 
 she maintained improvement with this medication at an 18-month follow - up ; medication taper was associated with re - emergence of hallucinations . 
 we briefly discuss csp and cv in the context of vulnerability to psychosis . 
 we examine whether isolated cv is a benign and incidental finding versus a biological risk factor for neuropsychiatric illness . 
 we suggest specific studies to resolve the uncertainty .