Keywords
traumatic brain injury - memory impairment
Introduction
Head injury is an important public health problem nowadays. In terms of number of
cases and the number of deaths, head injury is the leading factor. Moreover, severe
head injury remained a challenge to neurosurgeons and basic neuroscientists, as the
mortality and morbidity is very high in these cases.[1]
[7]
In traumatic brain injury (TBI), the external force results in varying degrees of
damage to the brain tissue.[8]
[10] The common causes of TBI include road traffic accidents (RTA), violence, injuries
at construction sites and sports, etc.[11]
[12] In India, RTA is the commonest cause of TBI on account of increasing vehicles and
inefficient road safety norms. Every minute there is one accident and every 4 minutes
there is a death in India. An epidemiological study of head injuries in the population
attending an emergency in the United Kingdom revealed head injury accounting for 3.4%
of all attendances per year. Among them, 10.9% injuries were of moderate to severe
grade.[13] Considering the fact that motor vehicular accident is the leading cause of head
injury worldwide, the World Health Organization dedicated the year 2004 to emphasize
on this aspect by giving the theme “road safety” tips/teaching on the occasion of
World Health Day.[14]
TBI results in damage to the brain due to external mechanical force such as rapid
acceleration, impact, blast waves, or penetration by projectile objects.[15] Brain injuries can be classified into mild, moderate, and severe categories according
to Glasgow Coma Scale (GCS). In mild head injury, GCS score is 13 to 15, moderate
9 to 12, and in severe head injuries GCS score is less than or equal to 8.[16] There are many features of head injury compromising higher mental functions among
the survivors but one of the primary symptoms after TBI is impaired word retrieval.[17] Word retrieval is the process of finding the correct terminology for picture, an
object, orthographic representation, or conversation, in which a person converts the
initial conception to a lexical version.[18] TBIs result in death and disability, especially in children and young adults.[19]
There is no literature available related to memory assessment in TBI patients in rural
areas of India as literacy has an impact on higher brain functions. Considering these
aspects of trauma on brain functioning, this study was conducted among the TBI survivors
attending the tertiary level health facility in rural setting to evaluate the various
correlates (age, gender, and other socio-demographic profile) of TBI and its effect
on memory functions of the victims following their treatment and discharge from hospital.
Aim and Objectives
To evaluate the memory status in mild and moderate brain injury study subjects following
treatment and discharge.
To describe the socio-demographic profile of the TBI cases in rural settings of India.
Materials and Methods
This was a cross-sectional study conducted at Uttar Pradesh University of Medical
Sciences, located at Saifai, in Etawah district of Uttar Pradesh, India. The study
was conducted during the period of October 2018 to January 2019 after obtaining prior
approval from the institutional ethical committee.
Cases who had been treated for TBI, attending the Neuro-surgery Outpatient Department
(OPD) during follow-up and who met the inclusion criteria, were included in this study.
Most of these were admitted to the Indoor Patient Department in the Neurosurgery Department
following TBI and were discharged after their appropriate case management. Those patients
who had history of any neurodegenerative illness, alcohol or substance abuse, cognitive
dysfunctions, and mental deterioration due to fulminant infection or neurological
disorders, including patients with repeated trauma or any chronic illness, were excluded
from the study. Patients who were unable to follow verbal as well as written commands
and could not be assessed by neurocognitive battery of tests were also excluded from
the study.
The subjects were enquired, and information was collected in the predesigned questionnaire
that comprised of various socio-demographic variables. All the subjects were first
examined by a faculty of Neurosurgery in the OPD and subsequently were referred for
memory evaluation that was done by single Physiology faculty trained in testing neurological
functions. The details of case history, mode of trauma, GCS score at admission, radiological
findings, investigations performed, and treatment details like surgery or conservative
management of cases were recorded from case files and discharge summaries. Memory
status of each case was evaluated using tests for immediate, short-, and long-term
memories. The memory functioning questionnaire was followed to assess this component
adequately. Patients from 3 weeks to 6 months following treatment of TBI were evaluated
for memory impairment.
We studied 65 patients of TBI. Patients were divided into two groups, namely mild
and moderate TBI, based on GCS scores at the time of admission. Patients with severe
GCS scores were not the part of our study.
Data thus collected were entered on Microsoft Excel worksheet and statistically analyzed
using Statistical Package for the Social Sciences software version 21.
Observations and Result
[Table 1] depicts that majority of these cases of TBI were in the age group of 20 to 39 years
(38.5%) and 40 to 59 years (36.9%). Among them, male patients were more (64.6%) as
compared with females. Majority of them were married (70.5%), residing in joint families
(61.5%), and educated below intermediate (72.3%). It also depicts that majority of
the subjects were either unemployed or having some private job.
Table 1
Sociodemographic profile of the study subjects (n = 65)
|
Variable name
|
Frequency (n)
|
Percentage
|
|
Age groups (in years)
|
|
≤19
|
10
|
15.4
|
|
20–39
|
25
|
38.5
|
|
40–59
|
24
|
36.9
|
|
60–79
|
6
|
9.2
|
|
Gender
|
|
Male
|
42
|
64.6
|
|
Female
|
23
|
35.4
|
|
Type of family
|
|
Nuclear
|
25
|
38.5
|
|
Joint
|
40
|
61.5
|
|
Educational status
|
|
Illiterate
|
2
|
3.1
|
|
Below intermediate
|
47
|
72.3
|
|
Intermediate
|
2
|
3.1
|
|
Graduate and above
|
14
|
21.5
|
|
Marital status
|
|
Unmarried
|
18
|
27.7
|
|
Married
|
46
|
70.8
|
|
Divorcee
|
1
|
1.5
|
|
Occupation
|
|
Not working/housewife
|
19
|
29.2
|
|
Student
|
11
|
16.9
|
|
Private job
|
19
|
29.2
|
|
Government job
|
4
|
6.2
|
|
Businessman
|
9
|
13.8
|
|
Others (farming, etc)
|
3
|
4.6
|
[Table 2] reveals that the proportion of memory loss was higher (80%) among diffuse axonal
injury (DAI), 50% in temporoparietal lobe injury, while it was 37.5% and 32.3% in
multiple lobe injury and frontal lobe injury, respectively. RTAs (75.4%) were the
commonest mode of injury. According to the GCS score at admission, it was observed
that 75.4% cases had mild brain injury while 16.9% had moderate TBI and 7.7% had severe
TBI. It was also observed that among all cases, 26.2% were operated for the brain
injury while the remaining 73.8% were managed conservatively. Immediate, short-, and
long-term memory status were assessed using various tests, which revealed that the
TBI had more effect on the short-term memory with 44.6% cases being depicted in [Table 3] unable to recall three words at an interval of 5 minutes.
Table 2
Pattern of traumatic brain injury in the cases (n = 65)
|
Variable name
|
Frequency (n)
|
Percentage
|
|
Site of injury
|
|
Frontal lobe
|
21
|
32.3
|
|
Tempo-parietal lobe
|
10
|
15.4
|
|
Occipital lobe
|
5
|
7.7
|
|
Multiple lobes involvement
|
24
|
36.9
|
|
Diffuse axonal injury (DAI)
|
5
|
7.7
|
|
Mode of injury
|
|
Road traffic accidents
|
49
|
75.4
|
|
Fall from height
|
10
|
15.4
|
|
Violence
|
3
|
4.6
|
|
Others (animal attack, etc.)
|
3
|
4.6
|
|
Glasgow outcome score at admission
|
|
Mild brain injury (13–15)
|
49
|
75.4
|
|
Moderate brain injury (9–12)
|
16
|
24.6
|
|
Glasgow outcome score at discharge
|
|
Mild brain injury (13–15)
|
58
|
89.3
|
|
Moderate brain injury (9–12)
|
7
|
10.7
|
|
Operation status
|
|
Done
|
17
|
26.2
|
|
Not done (conservatively managed)
|
48
|
73.8
|
Table 3
Memory status of study subjects (n = 65) determined using various memory tests
|
Memory test used
|
Bad
n (%)
|
Fair
n (%)
|
Good
n (%)
|
|
Immediate memory tests
|
|
Digit span test
|
11 (16.9)
|
40 (61.6)
|
14 (21.5)
|
|
Repeating three words
|
24 (36.9)
|
21 (32.3)
|
20 (30.8)
|
|
Naming months backward
|
16 (24.6)
|
25 (38.5)
|
24 (36.9)
|
|
Interrupted counting
|
9 (13.9)
|
21 (32.3)
|
35 (53.8)
|
|
Short-term memory tests
|
|
Thee-word recall at 5 min
|
29 (44.6)
|
16 (24.6)
|
20 (30.8)
|
|
How did you reach hospital
|
4 (6.2)
|
6 (9.2)
|
55 (84.6)
|
|
Long-term memory tests
|
|
Past event recall in past 25 y
|
10 (15.4)
|
21 (32.3)
|
34 (52.3)
|
Tests for analyzing memory status in patients using Frequency of Forgetting Scale
revealed that there was more difficulty in recall of phone numbers (35.4%) and personal
dates (32.3%). Approximately half of the cases (47.7%) had ([Table 4]) no difficulty in recognizing faces and name recalling.
Table 4
Memory status of study subjects (n = 65) determined using Frequency of Forgetting Scale for various tests
|
S. no.
|
Test used
|
Always
n (%)
|
Sometimes
n (%)
|
Never
n (%)
|
|
1
|
Forgetting names
|
8 (12.3)
|
27 (41.5)
|
30 (46.2)
|
|
2
|
Forgetting faces
|
6 (9.2)
|
28 (43.1)
|
31 (47.7)
|
|
3
|
Forgetting appointments
|
10 (15.4)
|
31 (47.7)
|
24 (36.9)
|
|
4
|
Forgetting things
|
15 (23.1)
|
28 (43.1)
|
22 (33.8)
|
|
5
|
Forgetting direction to places
|
15 (23.1)
|
26 (40.0)
|
24 (36.9)
|
|
6
|
Forgetting phone numbers
|
23 (35.4)
|
19 (29.2)
|
23 (35.4)
|
|
7
|
Forgetting personal dates
|
21 (32.3)
|
18 (27.7)
|
26 (40.0)
|
|
8
|
Forgetting what to buy from store
|
18 (27.7)
|
27 (41.5)
|
20 (30.8)
|
|
9
|
Forgetting what you are doing
|
17 (26.2)
|
27 (41.5)
|
21 (32.3)
|
|
10
|
Losing thoughts in conversation
|
16 (24.6)
|
26 (40.0)
|
23 (35.4)
|
[Table 5] shows that approximately half of the cases (44.6%) were unable to recall past events
occurred during the last 1 month following injury. Memory of remembering past events
was very good for events that occurred years back.
Table 5
Memory status of study subjects (n = 65) determined using Remembering Past Event Scale for various tests
|
S. No.
|
Test used
|
Very bad
n (%)
|
Fair
n (%)
|
Very good
n (%)
|
|
1
|
Events during last month
|
29 (44.6)
|
19 (29.2)
|
17 (26.2)
|
|
2
|
Events between 6 mo and 1 y
|
12 (18.5)
|
19 (29.2)
|
34 (52.3)
|
|
3
|
Events between 1 and 5 y
|
4 (6.2)
|
16 (24.6)
|
45 (69.2)
|
|
4
|
Events between 6 and 10 y
|
2 (3.1)
|
12 (18.5)
|
51 (78.4)
|
Discussion
Motor vehicle collisions and fall from height disproportionately affects the young
population (teenagers and young adults) and is more common in men than in women.[20] The present study has also revealed that more than half of the TBI subjects were
either teenagers or young adults and 64.6% of them were males.
It was observed that 75.4% of cases suffered from TBIs due to RTA, followed by fall
from height (15.4%). Various researchers in developed nations have reported fall from
height (28%), motor vehicular traffic accidents (20%), and assault (11%) as the leading
causes of TBI.[21]
[24] The highest incidence of motor vehicular traffic accidents has been reported in
the 15 to 19 years age group, while fall was the leading etiology in the 0 to 4 and
>75 years age groups.[25]
[29] Young age predilection can be explained on the basis that this being the productive
period of life, most of these are bread earners of family at this age group. Aged
drivers are most common victims for RTA as suggested by Owsley et al[30] and Bilban.[31] In puberty age group (32.3%), there are more chances of accidents because of increase
in testosterone level and catecholamine (epinephrine and norepinephrine), speeding
and drink driving, and less use of seat belt while driving or sitting in the car.[32]
[33] It was also observed that 70.8% of the TBI victims were married, which may be explained
on the basis of increased responsibilities or problematic relationship leading to
increase road risk behavior. Papez circuit, which is limbic associated structure,
functions primarily in the cortical control of emotion and memory storage and contains
centers that regulate aversion and gratification. Additional structures associated
with the Papez circuit include the prefrontal cortex, septum, and amygdala.[34] Damage to the mammillothalamic tract, ventral anterior nucleus, and ventral lateral
nucleus at the floor of third ventricle during TBI can result in memory and language
impairment.[35] Amnesia can be a result of disconnection of mamillary bodies from the Papez circuit.[36]
Memory loss may affect a person in many ways. Forgetfulness can happen because of
a busy lifestyle, depression, or as side effect of old age. However, memory impairment
can also be a result of traumatic event such as a brain injury or as a side effect
of Alzheimer’s or dementia. An article by the National Institute of Neurological Disorders
mentions that the most common side effect of TBI is memory loss.[37] In the present study, out of total 65 patients with TBI, 21 patients had frontal
lobe injury with 9 of them developing memory loss, that is, 42.9% cases. The temporoparietal
lobe was affected in 10 cases out of which 5 developed memory loss, that is, 50% cases.
The occipital lobe was affected in 5 cases but none developed memory loss. The multiple
lobes were involved in 24 cases with memory loss observed in 9 cases, that is, 37.5%.
DAI was observed in 5 cases; out of these, 4 developed memory loss, that is, 80% cases.
Memory loss may negatively impact an individual’s ability to perform activities of
daily living and function at job/office or as independently as they did prior to the
impairment. It may also impact an individual’s ability to work, remember work-related
appointments, or remember coworkers’ names. Most importantly, memory impairments may
impact an individual’s safety within the home or community. An individual suffering
from memory loss may forget to turn off the stove after cooking, or may even get lost
in the community and be unable to return home.[37] Further, 16.9% (n = 11) TBI patients were unable to perform digit span test (immediate memory test),
44.6% (n = 29) cases could not perform three-word recall at 5 minutes (short-term memory test),
and 15.4% (n = 10) cases could not perform long-term memory test. Chung et al has also reported
poorer performance on digital span test in cases with mild TBI affecting the superior
longitudinal fasciculus, which is critical for attention and short-term memory.[38]
Present study also revealed that 32.3% victims had frontal lobe injury with memory
loss and 75.4% of the cases had mild TBI. Kim et al[39] had also suggested that in mild TBI patients, memory-facilitating functions of frontal
lobe are comparatively preserved hence less chances of memory loss while memory functions
are more affected in moderate TBI patients. Temporal lobe has frontal lobe projection
that is necessary for various aspects of movement control, short-term memory, and
affect. In our study, probably this is the reason for short-term memory loss in 50%
of cases of TBI in rural setting. There was no memory impairment observed in TBI patients
with injury to occipital lobe. This is because occipital lobe is not involved in memory
storage and retrieval. Memory functions were significantly impaired in TBI with DAI
(based on magnetic resonance imaging findings) as 80% of DAI patients were not able
to perform various tests for memory assessment. DAI is the result of traumatic shearing
forces that occur when the head is rapidly accelerated or decelerated, as may occur
in car accidents, falls, and assaults.[40]
Conclusion
Memory play a major role in our life as it allows us to remember skills that we have
learned or retrieve information that is stored in the brain, or even recall a previous
moment that happened in the past. The study showed that memory loss was observed in
41.5% of TBI cases following treatment from 3 weeks to 6 months. Thus, periodic ongoing
memory assessment of individuals with TBI is important as neurological recovery can
keep occurring for several months or longer after certain types of severe brain injury.
The ongoing assessment can also be used to examine an individual’s response to rehabilitation
and to improve his/her life after the injury and thus help in the better management
of TBI cases. This can also assist in declaring these cases fit for memory-related
works.
