Neurocognitive and Affective Sequelae Following Complicated Mild and Moderate Traumatic Brain Injury: A Case Series
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.310110
Source of Support: None, Conflict of Interest: None
Keywords: Affective, neurocognitive impairment, psychological distress, traumatic brain injury
Traumatic brain injury (TBI) is a major public health concern. It creates primary and secondary effects such as the burden of medical cost, loss of income or productivity, disruption to the family, and impairment in day to day functioning of patients., In India, a substantial number of TBI patients require rehabilitation services every year. However, we are still lacking in providing rehabilitation services effectively, due to the lack of knowledge of post-TBI sequelae in these patients., Further, a better understanding of the impairment and outcome after TBI will be imperative for clinicians to plan effective treatment and rehabilitation strategies.
TBI is classified in a wide spectrum of severity that ranges from mild to severe. Studies have reported that mild TBI patients with neurocranial abnormality have shown poorer neurocognitive outcomes in comparison to mild TBI patients who have normal imaging findings.,, Researchers have called this group of mild TBI patients with neurocranial abnormality as complicated mild TBI or high-risk mild TBI group.
William, Harvey, and Eisenberg have found nonsignificant differences in neurocognitive and global outcomes between complicated mild TBI groups and moderate TBI groups at 1 to 3 months post injury. In a longitudinal prospective study, researchers have found that complicated mild TBI and moderate TBI patients have almost parallel neurocognitive and functional outcomes at 1 month and 1 year after brain injury. Similarly, Lange et al. have suggested that outcomes in patients with complicated mild TBI are quite similar to that of moderate TBI after 6 months of injury in military personnel who suffer from TBI. On the other hand, some researchers have suggested a linear relationship between injury severity and outcome. However, this trend is not found in the study related to outcomes of complicated mild TBI and moderate TBI group.,, Thus, there is a need for study to explore this contradictory issue. Further, despite consensus amongst clinicians that affective sequelae also create a significant impact on long-term outcomes in patients with TBI, it has been relatively less explored.
Most of the studies done in the Indian context have mainly focus on the outcome in uncomplicated mild TBI and severe TBI., Studies that compare neurocognitive as well as affective sequelae in TBI patient groups have included moderate TBI patients either with severe TBI or complicated mild TBI group.,, It is important to note that a moderate TBI group represents a significant proportion of TBI, but this group of patients is not explored much as an independent study group., Furthermore, mild head injury is often neglected area by the health care providers as patients with this diagnostic group exhibit lesser functional limitations as well as lessen chances of reoccurrence of symptoms as compared to moderate and severe TBI. However, it is evident from the literature that a substantial proportion of mild head injury patients suffers from persistent head injury symptoms and cognitive impairments that need to be examined. Therefore, the present study may be useful in understanding the outcome in patients with complicated mild TBI and moderate TBI.
Thus, the purpose of the study was twofold: firstly, to present the clinical series of the neurocognitive and affective profile of complicated mild and moderate TBI patients, and second, to compare the neurocognitive impairment, post head injury symptoms, and psychological distress in patients with complicated mild TBI and moderate TBI.
It is a comparative, cohort study conducted at neurosurgery department of one of the largest level I trauma center of India. Twenty-two patients with complicated mild TBI and 17 patients with moderate TBI, with an age range of 18–59 years and educated up to eighth grade were selected for the study by using a purposive sampling technique. Patients were categorized into complicated mild TBI and moderate TBI based on their Glasgow Coma Scale (GCS) score at admission and radiological evidence of intracranial abnormality. Complicated mild TBI had a GCS score between 13 and 15, along with radiological evidence of cerebral bleeding/abnormality. Patients with moderate TBI had GCS scores between 9 and 12 irrespective of radiological findings. Intracranial abnormalities of the patients with complicated mild TBI and moderate TBI were detected with the help of a CT scan and/or MRI. Patients who were able to read and comprehend Hindi language properly were included in the study. Patients who scored below four on digit span task were classified as having poor effort, and those patients were not included in the study. Patients with any major impairment in verbal communication, audibility, visualization, motor coordination, or physical amputation after injury, previous psychiatric disorder, and previous history of head trauma were excluded from the study. Written informed consent was obtained from patients to participate in the study. All the procedure of the study was followed in accordance with the Helsinki Declaration.
Neurocognitive assessment of patients was done using several subtests of National Institute of Mental Health and Neurosciences (NIMHANS) battery i.e., Digit Symbol Substitution Test (DSST) for mental processing speed; Controlled Oral Word Association Test (COWAT) for phonemic fluency; Verbal N-back test for working memory; Stroop test for response inhibition; Further, AIIMS memory scale for memory; and Trail Making Test (TMT) for visual search speed and mental flexibility were used. The obtained test scores were compared with the standard population score. The psychological distress was assessed with Hospital Anxiety and Depression scale (HADS). A score of ≥8 on the subtest indicates psychological distress on that affective component i.e., anxiety and depression. The post head injury symptoms were assessed with the Rivermead Post Concussive Symptoms Questionnaire (RPCSQ). Ratings of ≥2 on any symptoms indicate a problem with that symptom. Furthermore, patients having four or more symptoms on this questionnaire had post head injury symptoms.
The clinical case series of patients with complicated mild and moderate TBI regarding neurocognitive and affective sequelae were presented by using descriptive statistics [Table 1], [Table 2], [Table 3], [Table 4]. Socio-demographic characteristics were compared between complicated mild TBI group and moderate TBI group using Chi-square test/t-test. Further, the Chi-square test/Fisher's exact test was conducted to compare differences in the proportion of patients having neurocognitive deficit, psychological distress, and post head injury symptoms between the complicated mild TBI and moderate TBI group. Additionally, odds ratio (OR) was calculated to measure the magnitude of the differences. All statistical analyses were carried out using SPSS for Windows, Version 17 (SPSS Inc., Chicago, IL, USA). The power analysis was carried out using G*Power 3.0.10 statistical software.
Socio-demographic characteristics of complicated mild TBI and moderate TBI groups are presented in [Table 1]. There were no significant differences between patients with complicated mild TBI and moderate TBI in terms of gender (Fisher exact test, P = 0.464), age (t37 = 0.891, P > .05) level of education (Fisher exact test, P = 1.00), employment status (χ22, N = 39 = 1.078, P > .05), and marital status (χ21, N = 39 = 2.174, P > 0.05).
The neurocognitive profile of patients was presented in [Table 2]. It indicates that among the various neurocognitive domains, processing speed task was found as the most impaired cognitive function in patients with complicated mild (59.1%) and moderate TBI (76.5%). Further, an analysis was conducted to determine whether any significant group differences existed in the proportion of patients impaired on the neurocognitive performance of different cognitive domain.
This analysis [Table 2] revealed that there were no significant differences between complicated mild TBI and moderate TBI group on DSST (χ21, N = 39 = 1.30, P > 0.05, OR = 2.25), N Back 1 hit (Fisher exact test, P = 0.47, OR = 1.88), N Back 1 error (Fisher exact test, P = .21, OR = 4.17), N Back 2 hit (χ21, N = 39 = .09, P > .05, OR = 1.22), N Back 2 error (Fisher exact test, P = .70, OR = 1.75), Stroop (χ21, N = 39 = 2.46, P > .05, OR = 2.88), and AIIMS memory scale (Fisher exact test, P = .16, OR = 3.15). However, patients with moderate TBI were found significantly more impaired than patients with complicated mild TBI on the task of TMT-A (χ21, N = 39= 5.77, P < .05, OR = 5.14), TMT-B (χ21, N = 39 = 7.65, P < .01, OR = 6.96), and COWAT (χ21, N = 39 = 5.47, P < .05, OR = 4.89).
The [Table 3] indicates that higher numbers of patients with complicated mild TBI have reported anxiety (36.4%), depressive (40.9%), and post head injury symptoms (50.0%), whereas these symptoms are reported less frequently by the moderate TBI patients. Furthermore, complicated mild TBI patients have reported high anxiety (χ21, N = 39 = 5.02, P < 0.05, OR = 9.14) and depressive symptoms (χ21, N = 39 = 4.03, P < 0.05, OR = 5.19) in comparison to moderate TBI patients. Similarly, larger number of complicated mild TBI patients were in problematic category on posthead injury symptoms in comparison to moderate TBI patients (χ21, N = 39 = 4.36, P < .05, OR = 4.67).
Furthermore, a symptom-wise analysis was conducted to assess and compare the post head injury symptoms in complicated mild TBI and moderate TBI patients. The findings are shown in [Table 4]. Although, complicated mild TBI patients reported more post head injury symptoms in comparison to moderate TBI patients, these group differences were found nonsignificant [Table 4]. Lastly, the post hoc power analysis was carried out to assess the power efficacy of the present study. The analysis revealed the power of 0.40 for Fisher's exact test and 0.47 for the Chi-square test for two-tailed comparison when the alpha (α) was set at. 05 and sample size 17 and 22 for complicated mild TBI and moderate TBI group, respectively. Thus, the power of the present study is medium to large.
It is abundantly clear that TBI leads to various neurocognitive, behavioral, and psychological sequelae post injury. In light of this, the present study aimed to compare neurocognitive impairment, head injury symptoms, and psychological distress in patients with complicated mild TBI and moderate TBI.
In this study, a substantial number of TBI patients performed worse on processing speed tasks. The present findings were corroborated with previous literature that pertains to processing speed tasks as mostly impaired in TBI patients. TBI exerts traumatic forces in the brain that cause bruise, tear, bleeding, and other physical damage to brain. Damage in brain structure affects the connectome, which leads to impairment in processing speed.
The present study pertains that the neurocognitive impairment in complicated mild TBI group is quite similar to that of moderate TBI. Only the perceptual processing, mental flexibility, and phonemic fluency were found more impaired in moderate TBI group as compared to the complicated mild TBI group. The findings regarding non significant differences between complicated mild TBI and moderate TBI group on most of the neurocognitive functions are corroborated with the previous study.,, The researchers suggested that it may be due to the crude categorization of TBI, which is solely based on the GCS score.,, Over-reliance on GCS score may lead to poor choice of decision to categorize complicated mild TBI patients into the low vulnerable neurocognitive impaired group. It suggests that the categorization of TBI patients solely based on the GCS score is required to be reconsidered. Therefore, McNett has suggested that GCS score along with other injury-related indicators might be better in categorizing the TBI groups. It will help in lucidly estimate cognitive and affective sequelae of complicated mild and moderate TBI, and further plan their rehabilitation related strategy realistically.
Complicated mild TBI patients have reported more post head injury symptoms and psychological distress (i.e., anxiety and depression) in comparison to moderate TBI. These symptoms and complaints of TBI patients are mostly psychogenic in nature. Therefore, it can be stated that psychological factors may moderate the experience and reporting of symptoms. In this line, researchers have suggested that patients with severe injury have less awareness related to injury than patients with a mild injury. It may moderate the self-perception of impairment thus leading to exaggerated perception and experience of affective symptoms in less severely injured patients. Another possibility includes that patients with greater GCS scores receive a greater degree of reassurance by medical staff than comparatively less severely injured patients. It might be the reason that moderate brain injury patients have reported fewer symptoms and psychological distress than complicated mild brain injury patients. These findings suggest a requirement of holistic rehabilitation targeting neurocognitive as well as affective sequelae for patients with complicated mild and moderate TBI.
Thus, the current study makes a substantial contribution to the literature by addressing relatively less studied phenomenon i.e., affective component in complicated mild and moderate TBI group. Additionally, this is the first study in the Indian context that has compared affective component along with neurocognitive functioning in patients with complicated mild and moderate TBI. Patients with mild head injury are often overlooked by health care providers. However, present findings indicate that higher affective sequelae present in this group in comparison to moderate TBI; therefore, the health care providers should give similar consideration to the patients with this diagnostic group while extending the rehabilitation program. Furthermore, higher neurocognitive impairment and affective symptoms in complicated mild TBI group recommend an effective holistic rehabilitation for these patients as for moderate TBI patients.
Although, the present study endeavors to resolve paradox related to cognitive and affective sequelae of complicated mild TBI and moderate TBI patients, it has certain limitations. Firstly, the sample size of the present study remains relatively small. Secondly, various injury and noninjury factors are not incorporated in this study e.g., preinjury functioning and other bio-psycho-social factors. Therefore, incorporation of these factors in studying outcomes following complicated mild and moderate TBI patients constitutes an important future direction. In the future study, a longitudinal follow-up based study would be conducted to ascertain factual knowledge regarding temporal steadiness of affective sequelae of complicated mild and moderate TBI patients. Additionally, systematic longitudinal follow-up based study would be conducted with long-term problems including neuro-degeneration added to repeated mild head trauma. To a certain extent, these limitations restrict the generalizability of the present findings. To overcome these limitations, future studies could consider longitudinal, multi center study with larger sample size. Further, the inclusion of other severity groups of TBI for comparison will help in getting a better understanding of outcomes in TBI patients.
Lastly, it can be concluded that neurocognitive deficits and affective sequelae appear to be common and salient characteristics in TBI patients i.e., complicated mild TBI and moderate TBI. Therefore, an effective holistic rehabilitation program is needed for these groups. Further, moderate TBI and complicated mild TBI patients have almost similar neurocognitive functioning, but complicated mild TBI group has reported more affective sequelae. It is recommended that subsequent rehabilitation program for complicated mild TBI patients may be designed similar to that of moderate TBI patients.
The authors would like to thank the patients and their relatives, the clinical/nursing staff for cooperation from their behalf. The authors would also like to express special thanks to Dr. Usha Verma Srivastava, consultant clinical psychologist, for her general assistance and support.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients has/have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
[Table 1], [Table 2], [Table 3], [Table 4]