Introduction
The adage that the dead teach the living cannot be truer than in severe head injury. Most of the severely head injured patients, even with the best of treatments end up with high morbidity and mortality.
Traumatic brain injury refers to widespread pattern of injury throughout the brain caused by traumatic disruption of nerve cells, with particular type of injury to the axons. 1
There are four principal types of traumatic brain injury: diffuse vascular injury, diffuse axonal injury, hypoxic-ischemic encephalopathy and diffuse brain swelling. 2
Clinically, diffuse axonal injury is characterized by generalized injury to the axons leading to immediate unconsciousness and coma longer than 6 hours of duration. It is most commonly seen in road traffic accidents or fatalities and occasionally in assaults or fall. 3, 4
It has been proved that the diffuse injury to the axons can also occur in a variety of other non-traumatic pathological conditions such as cerebral hypoxia, hypoglycemia. 5
DAI is considered the most important factor in determining morbidity and mortality in victims of TBI and is the most common cause of post-traumatic coma, disability, and a persistent neuro-vegetative state. 6
It causes cognitive, physical and behavioural changes that compromise social re-integration, return to productivity, and quality of life of patients and their families. 7, 8
These changes persist beyond the acute phase of treatment and also continue for a long period after the traumatic event. Because the brain tissue is functionally impaired and not destroyed, so the brain may gradually regain normal function as the clinical condition stabilizes and neural connections are re-modelled due to plasticity. 9
Axonal injury is frequently a result of traumatic brain injury which may cause other focal damage in the brain like contusions, lacerations or haemorrhage.
Depending on the severity of trauma, the axonal injury can be focal, multi-focal or diffuse.
In focal and multi-focal axonal injury the damaged axons are seen in one or few locations in the supratentorial parts of the brain, mainly in the corpus callosum and internal capsule, but not in the infratentorial brain regions.
DAI is usually associated with rapid angular (rotational) acceleration and deceleration of the brain. 10 Inflammatory responses following neural injury have been suggested as an important mechanism in DAI.
Direct mechanical forces do not completely tear axons and they result in axonal retraction balls but stimulate and induce progressive changes that impede axonal transport, which subsequently results in the local swelling of the axon prior to detachment from its downstream segment. 11
The incidence of DAI is higher during autopsy than would be obvious on radiographic examination. 12 DAI represents approximately one- half of all intra-axial traumatic lesions. 13 No racial or sex predilection exists. DAI can occur at any age.
DAI may occur in utero, if a pregnant woman is subjected to sufficient force. 14
Understanding the variables associated with recovery after TBI, is needed for the development of individualized therapy, the evaluation of care provided by the family and doctors and the development of systematic care focused on patient rehabilitation.
It is also important for recognizing the efficacy and use of new techniques and treatments, as these should result in better patient outcome, recovery and survival.15
Axonal injury has been characterized histologically using silver stains, horse-radish peroxidase uptake and, most commonly in recent years with neurofilament or amyloid beta precursor protein.
Electroencephalography has been used for evaluation of the clinical assessment of consciousness to support the diagnosis and prognosis. Electrical activity of brain tissue may have good prognostic value after brain injury.
When performed from 15 days to 4 years after injury, EEG may provide an objective and quantitative measure of the severity of brain injury. It can detect early seizure activity, and provide information about sleep patterns during polysomnography. 16
Sleep disturbances are common after DAI, and may cause insomnia, hypersomnia, and altered sleep-wake cycles. 17
Annually, 262 per 100,000 inhabitants are admitted for TBI in Europe and it accounts for one third of all injury associated deaths in the United States. 18 TBI has profound socioeconomic impact. 19
Materials and Methods
The study was conducted in the department of neurosurgery, Sri Ramachandra institute of higher education and research, Porur, Chennai.
Sample
Material for this study was obtained from the patients admitted to Sri Ramachandra institute of higher education and research, Porur from September 2016 to December 2018. The study was conducted in a group of 55 cases admitted in the Department of Neurosurgery with a diagnosis of diffuse axonal injury who satisfied the inclusion and exclusion criteria. All symptoms and signs at the time of presentation and during the course in the hospital, which were recorded in the proforma. All the cases were diagnosed to have diffuse axonal injury on coumputed tomography scans and MRI brain. Their outcome and follow up statuses were noted. In the end the clinical presentation, course in the hospital and the outcome were analysed.
Inclusion criteria
Patients with severe TBI present with altered sensorium.
Multiple areas of injury on CT scans.
Any patient who demonstrates clinical symptoms disproportionate to his or her CT scan findings.
Instantaneous loss of consciousness and patients remaining in a persistent vegetative state,
Radiological evidence of diffuse axonal injury.
Adams classification
Grade I- Widespread axonal damage in white matter of cerebral hemispheres
Grade II- White matter damage extending to the cor- pus callosum with tissue tear hemorrhages
Grade III- Pathology of grade I-II and in addition, tis- sue tear hemorrhages in the brainstem
At the time of presentation
Once the patients were brought to the emergency department with the history of head trauma, patients underwent triage by the department of emergency medicine and received primary aid and resuscitation.
After the primary survey, cervical spine was stabilized with collar and patients with compromised airway and breathing or with GCS 8 or less were intubated and ventilated. Active fluid resuscitation was performed if circulation was at compromise.
Patients suspected to be at high risk for post traumatic seizures were loaded with intravenous fosphenytoin as per body weight. Tetnus toxoid was given to all patients. Patients with open wound, antibiotic was given. Once the patient was stabilized CT scan brain was done.
Neurological evaluation
Detailed history, stressing upon loss of consciousness, vomiting, seizures and ENT bleed was taken. Detailed neurological assessment was done according to GCS. Pupils were checked. Cardiovascular, respiratory, abdominal system were examined.
After all the assessment, patient was seen by orthopaedic, OMFS, Genrel surgery department and treatment was given accordingly.
Further management
According to the GCS patient is shifted to ICU or ward. Requirement of ICU admission depended on the severity of head injury and GCS. In ICU, patients were monitered by neurosurgeon and neuroanesthetist. Serial assessment of patients in ICU was done and some patients who showed neurological deterioration were intubated
Results
Patients with GCS 3-8 had GOS 1-5. Patients with GCS of 9-12 had GOS of 3-5 and Patients with GCS of 13-15 had GOS of 4-5. Most patients in our study had grade 2 DAI and GOS 4.
Table 1
Profile of the patients enrolled (n-55)
Table 2
Age distribution of patients with diffuse axonal injury (n-55)
|
Age(years) |
Number |
Percentage (%) |
|
1 - 20 |
6 |
10.9 |
|
21 - 40 |
26 |
47.3 |
|
41 - 60 |
17 |
30.9 |
|
61 - 80 |
5 |
9.1 |
|
>80 |
1 |
1.8 |
Table 3
Gender distribution of patients enrolled (n-55)
|
Gender |
Number |
Percentage (%) |
|
Male |
46 |
83.6 |
|
Female |
9 |
16.4 |
Table 4
Distribution of patients according to mode of injury (n-55)
|
Mode of injury |
Number |
Percentage (%) |
|
Road Traffic Accident(RTA) |
41 |
74.5 |
|
Fall |
8 |
14.5 |
|
Others |
6 |
11.0 |
Table 5
Distribution of patients according to stay in hospital (n-55)
|
Hospital stay (days) |
Number |
Percentage (%) |
|
1 - 7 |
9 |
16.4 |
|
8 - 14 |
16 |
29.1 |
|
15 - 21 |
8 |
14.5 |
|
22 - 28 |
5 |
9.1 |
|
> 28 |
13 |
23.6 |
|
NA |
4 |
7.3 |
Table 6
Distribution of patients according to symptoms (n-55)
|
Presenting symptoms |
Number |
Percentage (%) |
|
Loss of consciousness |
55 |
100.0 |
|
Headache |
51 |
92.7 |
|
Vomiting |
38 |
69.1 |
|
ENT bleeding |
20 |
36.4 |
|
Seizures |
6 |
10.9 |
Table 7
Distribution of Glasgow Coma Scale among patients at admission (n-55)
|
Glasgow Coma Scale |
Number |
Percentage (%) |
|
3 - 8 |
30 |
54.5 |
|
9 - 12 |
11 |
20.0 |
|
13 - 15 |
14 |
25.5 |
Table 8
Distribution of patients according to intubation requirement (n-55)
|
Intubation required |
Number |
Percentage (%) |
|
Yes |
29 |
52.7 |
|
No |
26 |
47.3 |
Table 10
Follow-up Status of patients enrolled in the study (n-55)
|
Follow-up status |
Number |
Percentage (%) |
|
Died |
8 |
14.5 |
|
LAMA |
4 |
7.3 |
|
Followed-up |
43 |
78.2 |
Table 11
Distribution of Glasgow Coma Scale among patients at Follow-up (n-43)
|
Glasgow Coma Scale |
Number |
Percentage (%) |
|
3 - 8 |
3 |
7.0 |
|
9 - 12 |
7 |
16.3 |
|
13 - 15 |
33 |
76.7 |
Table 12
Distribution of patients according to morbidity reported (n-43)
|
Morbidity |
Number |
Percentage (%) |
|
Yes |
11 |
25.6 |
|
No |
32 |
74.4 |
Table 13
Results of Glasgow outcome scale among patients enrolled (n-55)
|
Glasgow outcome scale Grade |
Number |
Percentage (%) |
|
NA |
4 |
7.3 |
|
Graded |
51 |
92.7 |
|
5 |
10 |
19.6 |
|
4 |
18 |
35.3 |
|
3 |
12 |
23.5 |
|
2 |
3 |
5.9 |
|
1 |
8 |
15.7 |
Table 14
Distribution of patients according to grade of DAI (n-55)
|
DAI Grade |
Number |
Percentage (%) |
|
1 |
7 |
12.7 |
|
2 |
36 |
65.5 |
|
3 |
12 |
21.8 |
Table 15
MRI status of patients enrolled (n-55)
|
MRI done |
Number |
Percentage (%) |
|
Yes |
20 |
36.4 |
|
No |
35 |
63.6 |
Table 16
Glasgow coma score (GCS) at admission among patients underwent MRI and their Glasgow outcome score (GOS) (n-20)
|
Glasgow outcome score(GOS) |
Glasgow coma scale(GCS) |
|||
|
3 - 8 |
9 - 12 |
> 12 |
Total |
|
|
1 |
0 |
0 |
0 |
0 |
|
2 |
0 |
0 |
0 |
0 |
|
3 |
1 |
0 |
0 |
1 |
|
4 |
2 |
3 |
8 |
13 |
|
5 |
0 |
0 |
6 |
6 |
|
Total |
3 |
3 |
14 |
20 |
Table 17
Tracheostomy status of patients enrolled (n-55)
|
Tracheostomy done |
Number |
Percentage (%) |
|
NA |
4 |
7.3 |
|
Yes |
15 |
27.3 |
|
No |
36 |
65.5 |
Table 18
DAI grade of patients according to their Glasgow coma scale (GCS) (n-55)
|
DAI grade |
N |
Glasgow coma scale |
X2 |
df |
p-value |
|||||
|
3 - 8 (n-30) |
9 - 12 (n-11) |
13 - 15 (n-14) |
||||||||
|
N |
% |
N |
% |
N |
% |
|||||
|
1 |
7 |
0 |
0.0 |
3 |
42.9 |
4 |
57.1 |
19.412# |
4 |
0.0001* |
|
2 |
36 |
18 |
50.0 |
8 |
22.2 |
10 |
27.8 |
|||
|
3 |
12 |
12 |
100.0 |
0 |
0.0 |
0 |
0.0 |
|||
Table 19
Glasgow outcome scale (GOS) of patients according to their Glasgow coma scale (GCS) (n-51)
Discussion
This longitudinal, observational study was conducted in 55 patients of Diffuse Axonal Injury in the department of neurosurgery, Sri Ramachandra institute of higher education and research, porur, Chennai from September 2016 to December 2018.
The clinical features, radiological features and outcomes of patients with diffuse axonal injury were noted and compared with observations made by other authors in their studies.
All the cases presenting to emergency department with history of head injury were subjected to CT Brain, out of which 55 patients were included in the study.
Diffuse Axonal Injury refers to widespread pattern of injury throughout the brain caused by traumatic disruption of nerve cells, with particular injury to the axons.
It is most commonly seen in road traffic accidents and occasionally in assaults or fall.
There can be multiple areas of injury on CT scans.
Any patient who demonstrates clinical symptoms disproportionate to his or her CT scan findings is also categorised as diffuse axonal injury
The consequences of DAI can be cognitive, physical, and behavioural changes that compromise social behaviour, return to work, and quality of life of patients and their families.
It is graded by CT Brain and MRI Brain.
Adams classification on the basis of MRI Brain
Grade I- Widespread axonal damage in white matter of cerebral hemispheres
Grade II- White matter damage extending to the corpus callosum with tissue tear haemorrhages
Grade III- Pathology of grade I-II and in addition, tis- sue tear haemorrhages in the brainstem
Conclusion
Out of 55 cases 46 were male and 9 were females.
Majority of patients were in the age group of 21-40 years and mean age was 38.41 yrs. Youngest patient was 17years and oldest was 83 years old.
Most common mode of injury was Road traffic accident, in 41 patients (74.5%), fall in 8 patients (14.5%) and other mode of injury like work place injury etc in 6 patients (10.9%).
Duration of Loss of consciousness was more than 6 hours in majority of patients.
Most common presenting complaint seen in all patients in our study was headache and vomiting.
In this study group 30 pts had GCS 3-8, 11 pts had GCS of 9-12 and 14 pts had GCS of 13-15.
Out of 55 patients 29(52.7%) were intubated and 15(27.2%) patients underwent tracheostomy.
All patients (55) underwent CT but only 20 patients underwent MRI. Other 35 patients didn’t undergo MRI due to logistic reason.
As no classification of DAI is available on CT scan finding, grading of DAI for patients who had undergone CT scan is done based on MRI grading system of DAI.
Seven patients (12.7%) had grade 1 DAI, 36 patients (65.5%) had grade 2 DAI and 12 patients (21.8%) had grade 3 DAI.
Patients with diffuse axonal injury grade II and III had maximum days of hospital stay as compared to grade I.
Minimum hospital stay was 1 day and maximum was 64 days.
Inotropes were started on 13 patients in which 11 patients were under GCS 3-8 and 2 patients under GCS 9-12.
Maximum follow up was one and half years.
Outcome of the patients were noted according to Glasgow outcome scale.
Out of 55 patients 8 patients expired.
Eight (15.7%) patients had GOS 1, 3 (5.9%) patients had GOS 2, 12 (23.5%) patients had GOS 3, 18 (35.3%) patients had GOS 4 and 10 (19.6%) patients had GOS 5.
Most of the patients in this study had grade 2 DAI. Good recovery was seen in grade 1 and 2 DAI and high morbidity and mortality in grade 3 DAI
Patients with GCS of 3-8 had GOS 1-5. Patients with GCS of 9-12 had GOS of 3-5 and Patients with GCS of 13-15 had GOS of 4-5. Most patients in our study had grade 2 DAI and GOS 4.
The available world literature has observed cognitive, physical, and behavioral changes, outcome in patints with diffuse axonal which have been mentioned earlier. In our study similar observations were made with in concerance with reference to studies. The major difference being the mortality rate which again proves that RTA and head injuries cause loss of life and burden to state and family.
Acknowledgement
I wish to place my deep sense of gratitude and gratefulness to the guiding light and pillar of my strength, my esteemed teacher and my guide, Dr. K. Ganesh, Professor and HOD, Department of Neuro Surgery, Sri Ramachandra Institute of Higher Education and Research, who has always been a source of immense inspiration. His invaluable advice kept me motivated and dedicated toward my work for the manuscript and towards mankind.
Article
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