in last two decades following advances in neuroimaging studies , there has been growing interest in studying the neurological soft signs ( nss ) and cognitive function in obsessive - compulsive disorder ( ocd ) , a disorder which was earlier explained only on basis of psychoanalytical theories .
dysfunction in brain functioning implies that ocd should be characterized by neurological abnormalities which can be either 
 hard signs refer to impairment in basic motor , sensory , and reflex behaviors .
in contrast , nss are described as nonlocalizing neurological abnormalities that can not be related to impairment of a specific brain region or are not believed to be part of a well - defined neurological syndrome . however , even if they are nonlocalizing , some nss can suggest dysfunction in particular neural networks and , thus , can give additional information concerning abnormalities in the functional organization that characterize some psychiatric diseases .
cognition denotes a relatively high level of processing of specific information including thinking , memory , perception , motivation , skilled movements , and language .
a constellation of these core cognitive deficits in various combinations and severity also have a role in the explaining the neuroanatomy and psychopathology of the disease .
efforts for assessment of nss in ocd have met with variable success with some studies reporting significantly higher nss in the domains of complex motor coordination , involuntary movements , mirror movements , and primitive reflexes in patients with ocd .
however , there has been lack of consistency and specificity in the findings of the studies .
studies have reported impairment in visuospatial ability , executive function , attention , concentration , and working memory in ocd subjects .
these deficits further lead to impairment in social and occupational functioning leading to increased distress and disability in ocd patients .
although western studies have looked at these issues , there are few studies from india investigating the role of nss and cognitive deficits in adult ocd .
the study was conducted in the outpatient department of psychiatry in a tertiary care general public hospital after obtaining permission of the institutional review board .
the study group comprised fifty subjects with the international classification of diseases-10 diagnosis of ocd , with age more than 18 years .
subjects with intellectual subnormality , organic mental disorders , and spectrum of psychotic disorders ( schizophrenia , schizoaffective disorder , and bipolar disorder ) as the major axis i disorder were excluded from the study .
the control group comprised fifty subjects matched with study group for age and education with no past , present , or family history of major psychiatric disorder in first - degree relatives .
all participants gave written informed consent to a protocol approved by the institutional review board .
nss were assessed using heidelberg soft neurological signs scale , a 16-item scale . a sufficient internal reliability and
it assess five factors : motor coordination ( ozeretski test , diadochokinesis , pronation - supination , finger - to - thumb opposition , and speech articulation ) , sensory integration ( gait , tandem walking , and 2-point discrimination ) , complex motor tests ( finger - to - nose test , fist - edge - palm test ) , right / left and spatial orientation ( right / left orientation , graphesthesia , face - hand test , and stereognosis ) , and hard signs ( includes arm - holding test , mirror movements ) .
it assesses six cognitive domains : short - term memory recall task ( two learning trials of five nouns and delayed recall after approximately 5 min ) , visuospatial abilities ( clock - drawing task and a three - dimensional cube copy ) , executive functions ( alternation , phonemic fluency , and verbal abstraction task ) , attention , concentration and working memory ( sustained attention task , a serial subtraction , digits forward and backward ) , language ( naming , repetition , aforementioned fluency task ) , and orientation to time and place .
all analyses were performed with the statistical package for social sciences software ( spss inc . ,
whitney u - test for comparison of mean between the study and control group was used for the analyses . for correlational analyses , pearson correlation ( p )
the mean age of ocd subjects was 30.62 years with range between 18 and 59 years . among them , 64% of the subjects were males , 56% of the subjects were college educated , 34% were up to secondary level , 6% were primary educated , and 4% were illiterate .
as revealed in table 1 , scores were significantly higher in ocd subjects in all the tests for motor coordination ( ozeretski 's test , p = 0.001 ; diadochokinesis , p < 0.001 ; pronation - supination , p = 0.004 ; finger - to - thumb opposition , p < 0.001 ; and speech articulation , p < 0.001 ) , sensory integration ( gait , p = 0.002 ; tandem walking , p < 0.001 ; and 2-point discrimination , p < 0.001 ) , complex motor tasks ( finger - to - nose test , p < 0.001 and fist - edge - palm test , p < 0.001 ) , and hard signs ( arm - holding test , p < 0.001 and mirror movements , p < 0.001 ) .
ocd subjects scored significant higher in all the tests of right / left and spatial orientation ( right / left orientation , p < 0.001 ; graphesthesia , p = 0.007 ; and stereognosis , p
< 0.001 ) except for test of sensory extinction ( face - hand test , p = 1.000 ) .
comparison of neurological soft signs as shown in table 2 , ocd patients fared worse on all subsets of montreal cognitive assessment compared to controls .
ocd patients showed significant deficits in short - term memory task ( p < 0.001 ) , visuospatial ability ( p
< 0.001 ) , attention , concentration and working memory ( p < 0.001 ) , and language ( p < 0.001 ) .
there was no significant difference for orientation ( p = 0.53 ) between ocd patients and controls .
the mean age of ocd subjects was 30.62 years with range between 18 and 59 years . among them , 64% of the subjects were males , 56% of the subjects were college educated , 34% were up to secondary level , 6% were primary educated , and 4% were illiterate .
as revealed in table 1 , scores were significantly higher in ocd subjects in all the tests for motor coordination ( ozeretski 's test , p = 0.001 ; diadochokinesis , p < 0.001 ; pronation - supination , p = 0.004 ; finger - to - thumb opposition , p < 0.001 ; and speech articulation , p < 0.001 ) , sensory integration ( gait , p = 0.002 ; tandem walking , p < 0.001 ; and 2-point discrimination , p < 0.001 ) , complex motor tasks ( finger - to - nose test , p < 0.001 and fist - edge - palm test , p < 0.001 ) , and hard signs ( arm - holding test , p < 0.001 and mirror movements , p < 0.001 ) .
ocd subjects scored significant higher in all the tests of right / left and spatial orientation ( right / left orientation , p < 0.001 ; graphesthesia , p = 0.007 ; and stereognosis , p
< 0.001 ) except for test of sensory extinction ( face - hand test , p = 1.000 ) .
as shown in table 2 , ocd patients fared worse on all subsets of montreal cognitive assessment compared to controls .
ocd patients showed significant deficits in short - term memory task ( p < 0.001 ) , visuospatial ability ( p
< 0.001 ) , attention , concentration and working memory ( p < 0.001 ) , and language ( p < 0.001 ) .
there was no significant difference for orientation ( p = 0.53 ) between ocd patients and controls .
nss were present to a significantly greater extent in ocd patients than controls in our study .
these findings are in accordance with numerous prior studies reporting significantly higher total nss scores in ocd subjects .
nss in our ocd patients were significantly higher in all the subscales of motor coordination , sensory integration , complex motor tests , right / left and spatial orientation , and hard signs .
higher scores for motor coordination , complex motor tasks , and hard signs seen here are also reported by other studies .
although the initial study by hollander 1990 did not report higher scores in sensory integration and right / left and spatial orientation , subsequent studies by bolton 1998 and guz 2004 have reported higher scores also on these subtests as well .
bolton 1998 also demonstrated that ocd subjects had neurological signs in certain categories such as motor coordination , sensory integration , hard signs , tardive dyskinesia , catatonic , and extrapyramidal signs similar to patients with schizophrenia .
the significant impairment in cognition observed in our study in the domains of visuospatial ability , executive function , attention , and working memory is in accordance to other studies .
visuospatial and visuoconstructional deficits in tests using ability to draw complex figures are the most consistent findings in ocd .
ocd patients have shown impairment on both , verbal memory on measures of new learning such as the california verbal learning and nonverbal memory such as visual reproduction and delayed recognition of figures .
these findings may suggest impairment in encoding and retrieval of new information in ocd patients .
similarly , the finding of short - term memory task deficit in this study may be explained on the above basis as well as the impaired attention seen in our patients .
although recent research has reported deficit in verbal fluency in ocd , there is scanty literature studying other language deficits such as repetition and naming .
the orbitofrontal cortex and basal ganglia are the most consistently associated with ocd in imaging studies , ocd symptoms attributed to be caused by the hyperactive orbito - fronto - thalamic circuit .
these imaging findings are corroborated by the finding that disrupting connections between ofc , acc , thalamus , and basal ganglia by means of anterior capsulotomy or cingulotomy result in a symptomatic improvement in most ocd patients .
further ocd symptoms are reported damage to the basal ganglia , especially the caudate and orbitofrontal cortex . also ,
dysfunction of the basal ganglia secondary to a streptococcal infection or encephalitis lethargic has also been associated with the development of ocd .
although nss are described as nonlocalizing neurological abnormalities , neuroimaging studies have suggested associations of nss with activation changes in the sensorimotor cortex , supplementary motor area , cerebellum , basal ganglia , and thalamus .
similarly , the cognitive deficits , namely , visuospatial , executive , attention , concentration , and memory observed in the study are indicative of the underlying neuroanatomical and neurophysiological changes , mainly in the frontal lobe .
the presence of confounding factors such as comorbid depressive or psychotic symptoms is known to influence nss and cognition . however , study by trivedi et al . comparing ocd patients without any other comorbid axis i disorder with healthy controls reported significant impairment in executive function , sustained attention abilities , and spatial working memory in ocd patients .
similarly , rao et al . reported significant neuropsychological deficits in thirty recovered ocd patients in comparison with thirty matched healthy controls .
these findings are indicative that neuropsychological deficits are possibly stated independent and are indicative of underlying neuroanatomical deficit .
as this was a cross - sectional study , the effect of therapeutic interventions on the scores of nss and cognitive functions could not be assessed .
the presence of nss and cognitive deficits in ocd is indicative of underlying neuroanatomical and neurophysiological dysfunction and that ocd is a brain disease .
ocd affects the younger population and is known to cause significant impairment in individual social and occupational productivity .
this disability can now be linked to the defective higher mental functions secondary to neurological dysfunction and not just the obsessive symptomatology as thought previously .
 objective : modern research on obsessive - compulsive disorder ( ocd ) indicates that the primary cause of ocd , which was earlier explained only on basis of psychoanalytical theories , is biological . 
 our study attempts to investigate the neurobiological signs in form of soft neurological signs and cognitive function in ocd.methods:a cross sectional study was conducted at psychiatric facility of seth g.s . 
 medical college and kem hospital.materials and method:50 ocd patients and age- and education - matched controls were selected for the study . 
 established instruments were used to assess the neurological soft signs ( nss ) and the cognitive deficits.results:ocd patients had significant more nss in tests for motor coordination , sensory integration , complex motor tasks , hard signs , and right / left and spatial orientation . 
 cognitive deficits in the domains of visuospatial ability , executive function , attention , and working memory were significantly more in ocd patients compared to controls.conclusion:our study highlights the role of biological factors in form of soft neurological signs and cognitive dysfunction in the development of the ocd . 