Diffuse Axonal Injury after severe head trauma

Summary Diffuse Axonal Injury (DAI) is a well known entity that affects many patients with severe head trauma. Classically DAI has been considered the pathological substrate of those cases rendered unconscious at the moment of impact and in which the CT scan does not show mass lesions. Diffuse axonal damage is almost always related to mechanisms of injury in which the rotational acceleration produces shear and tensile strains of high magnitude. In this paper we present a group of 24 patients with a severe head injury in whom the postmortem examination demonstrated unequivocal signs of DAI.Widespread axonal retraction balls, located preferentially in the centrum semiovale and internal capsule were the most constant histological finding. We divided the entire series into two subgroups. One group (15 cases), included all the patients in whom the CT scan did not demonstrate mass lesions. In the second group (9 patients) we considered patients with a diffuse axonal injury in whom the CT scan additionally demonstrated a mass lesion (6 acute subdural haematomas, 2 intracerebral and 1 extradural haematoma). The mean age of the entire group was 26 years.Twenty two patients were injured in a road traffic accident, the remaining two fell from a considerable height. All were rendered immediately unconscious on impact. Diffuse brain damage is a common finding in patients with a severe head injury and immediate coma in whom the CT scan does not show mass lesions. Diffuse axonal injury can also appear in connection with a wide spectrum of focal lesions (acute subdural haematoma, basal ganglia haematoma etc.). Associated shear injuries of the brain in this latter group, could justify the poor outcome that certain groups of patients had in spite of the rapid surgical treatment and aggressive control of intracranial pressure.     

Post-traumatic brain stem distortion: a case report

BACKGROUND

Primary traumatic brain stem injury (BSI) lesions are found most frequently in the dorsal or dorsolateral midbrain, whereas distortion of the brain stem itself is exceedingly rare.

CASE REPORT

We present a 20-year-old woman with a rare brain stem injury caused by a violent motor vehicle collision. Magnetic resonance imaging at 2 months after injury revealed marked brain stem distortion with loss of the normal shape at the midbrain and pons, which were displaced anteriorly in association with the fracture of the clivus. Moreover, the medulla oblongata showed a loose winding configuration. At discharge about 5 months after injury, the Glasgow Outcome Scale was severe disability.

CONCLUSION

This BSI was caused by reciprocal actions of fracture of the clivus and the direct effect on the brain stem caused by acceleration or rotational forces.     

Prognostic Factors in Postraumatic Severe Diffuse Brain Injury

Summary  It is usually defficult in clinical practice to establish factors affecting final outcome in patients suffering severe diffuse brain injury (SDBI), due to the absence of specific semiology.  Methods. We studied retrospectively 160 consecutive patients with criteria of SDBI. We performed a statistical analysis of epidemiological, clinical and radiological factors, and relationship with final outcome.  Result. 35% of patients with severe head injury presented SDBI. Sixty percent were 15–35 year old and 73% male. More than 45% of the patients presented GCS 3 or 4. On CT performed during the first 24 h, haemorrhagic lesions appeared in white matter in 35% and subarachnoid haemorrhage was observed in 28%. During the first 24 h., 66% of patients presented values of intracranial pressure (ICP) above 20 mm Hg and a 33% below 20 mm Hg. Twenty percent of the patients had ICP>20 mm and no response to treatment. According to the Glasgow Outcome Scale (GOS), mortality of more than 50% and 25% of patients with persistent vegetative state or severe disability were observed.  Conclusions. Clinical evaluation, early CT findings, ICP values and their response to medical treatment and clinical complications were found to be related (p<0.05) to final outcome (GOS).     

Primary brain stem tumours

Summary The material consisted of 31 patients with primary brain stem tumours who were investigated retrospectively. Twenty patients were younger than 16 years of age (range: 1 1/2–65 years). The mean age was 11 years. The female/male sex ratio was 19/12. Histological diagnoses were available for 18 patients. All of the verified tumours were gliomas. The diagnoses in 12 cases were made by section or biopsy; in 15 by standard clinical and radiological examinations and in 4 by exploratory operations.Headaches, mental changes, speech and gait disturbances were the most common symptoms at the onset of the illness and at the time of diagnosis. The mean latency period between the emergence of symptom(s) until diagnosis was 4 months (range: 1/2–48 months). Amongst the dominant objective findings were failure of the V, VI and VII cranial nerves, pyramidal tract symptoms, ataxia and nystagmus, occurring singly or in combination.Pneumoencephalograms disclosed characteristic changes in 25 patients (83%).Fourteen patients (45%) received radiation treatment, from which 5 (36%) obtained a temporary remission in their symptoms. The postdiagnostic mean survival period for the patients was 15 months (range: 0–92 months).The survival time was found to depend on the number of damaged cranial nerve nuclei at the time of diagnosis and on the degree of severity and duration of the accompanying hydrocephalus. The prognosis was unfavourable, as the percentage of patients who survived for 2 years was only 6%, and a total duration of illness longer than 2 years occurred in only 7 patients. None of the patients were still surviving at the conclusion of this investigation.     

Frequency of primary brain stem lesions after head injuries

Summary Analysis of level of brain stem dysfunction, evolution, and CT scan profile was made on 76 cases of head injuries with prolonged unconsciousness and without hemispheric focal lesion and midline shift on CT scan. Eleven cases were considered normal on CT scan. The CT scan aspect of primary brain stem lesion was identified in 31.5% of these series, and in 14.5% of all severe head traumas (186 cases), from which this series is taken. Primary and secondary CT scan profiles were observed whatever the clinical level of dysfunction and its evolution. Pontine lesions were mainly associated with haemorrhage in the brain stem and diffuse brain swelling; but minimal signs (cortical level) and benign outcome can also be related to axial haemorrhage. These results emphasize the frequency of primary brain stem lesions and the value of CT scan in head injuries.     

Barbiturates in severe head injuries?

Possible mechanisms for the therapeutic effects of barbituric acid derivatives in severe head injuries have been discussed for half a century. In the following, a survey of the literature, and a discussion of three controlled clinical studies available until now is presented. A proven effect in terms of a beneficial long-term outcome for all injured patients has not been established.On the other hand there might be a subgroup of patients with an intact CO₂ reactivity of the brain vessels who may profit from barbiturates administered after head trauma.Dedicated to Marianne and Gerhard Winkler     

The role of MR imaging in assessing prognosis after severe and moderate head injury

Purpose  The objective of this work is two-fold: to determine the role of MRI findings in establishing the prognosis of patients with moderate and severe traumatic brain injury (TBI) admitted to our centre, measured with different outcome scales; and to determine in which patients the information given by MR findings adds prognostic information to that from traditional prognostic factors. Methods  One hundred patients suffering moderate or severe head injury in whom MRI had been performed in the first 30 days after trauma were included. The MRI was evaluated by two neuroradiologists who were not aware of the initial CT results or the clinical situation of the patients. Outcome was determined 6 months after head injury by means of the extended version of the Glasgow Outcome Scale. The prognostic capacity of the different factors related to outcome was compared by the analysis of receiver operating characteristic (ROC) curves and the area under the curve (AUC) for each factor. Results  There exists a clear relation between the depth of the traumatic lesions shown on MRI, and their classification by the proposed scale, and the outcome of patients suffering traumatic brain injury determined by different scales 6 months after injury. Conclusions  The anatomical substrate of TBI depicted by MRI could be a useful prognostic tool in patients suffering moderate and severe head injury. Patients with a score of 4 or less on the motor subscale of the GCS scale are those who could benefit most from the prognostic information provided by MRI.     

Brain swelling and brain oedema in acute head injury

Summary Chronological changes in diffuse brain swelling and brain oedema were studied in repeated CT studies following a closed head injury. These findings were compared with changes in intracranial pressure (ICP). The grades of diffuse brain swelling were classified into mild, moderate and marked according to the CT findings. Planimetry of low density areas of brain oedema was carried out on repeated CT images. Diffuse brain swelling was recognized in 71 of patients shortly after the head injury and subsided within days 3–5. Brain oedema first appeared 24 hours post injury and did not reach its maximum size and distribution before days 5–8. Thus, these two events can be clearly separated. The intracranial pressure reflected the course of the brain swelling and was not very high during the presence of maximum oedema.     

Multimodality electroneurophysiological findings in intra-axial and extra-axial lesions of the brain stem

Summary In 330 patients with a space occupying lesion of the posterior cranial fossa, the blink (BR) and masseter (MR) reflexes and brain stem auditory (BAEP) and somatosensory evoked potentials (SEP) were registered. The aim of our study was to look for electrophysiological criteria of differentiating between lesions within or outside the brain stem. The ipsilateral loss of BAEP in cerebellopontine angle tumours and the altered SEP in tumours within the brain stem turned out as frequent, almost specific findings. Prolonged ipsi- and contralateral late BR responses and prolonged MR responses, a long somatosensory central conduction time of the SEP and a prolonged wave III latency as well as a prolonged interpeak latency of the BAEP are not indicative but highly suspicious for a lesion within the brain stem. Prolonged early responses of the BR together with prolonged interpeak latencies of the BAEP are characteristic findings in cerebello-pontine angle tumours.     

Dexamethasone in severe head injuries

Summary The results of a double-blind-study on the effects of placebo, a low dose and a high dose of dexamethasone on severe closed head injury are presented. 95 patients were selected and carefully analyzed according to mortality, neurological course and symptoms, midbrain lesions and final outcome. The results demonstrate that dexamethasone, particularly given in high doses, reduces mortality and improves the neurological course. The steroid treatment seems to improve chances as well as quality of survival. Apart from the dose, timing of administration is of great importance.

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Zusammenfassung Es werden die Ergebnisse einer Doppel-Blind-Studie über die Auswirkungen von Placebo, niedriger und hoher Dosierung von Dexamethason bei schweren gedeckten Schädel-Hirn-Verletzungen mitgeteilt. Die Daten von 95 Patienten wurden sorgfältig analysiert in bezug auf Mortalität, neurologischen Verlauf und neurologische Symptome, Mittelhirn-Läsionen und Endzustand. Die Ergebnisse zeigen, daß Dexamethason, besonders in hoher Dosis, die Mortalität senkt und den neurologischen Verlauf bessert. Die Steroid-Behandlung scheint sowohl die Überlebens-Chance wie auch -Qualität zu verbessern. Neben der Dosierung kommt dem Zeitpunkt der Verabreichung große Bedeutung zu.

     

Relation of visual field defects to neuropsychological outcome after closed head injury

Summary Neuropsychological outcome within two years after injury was determined in 159 head injured patients who were classified into three groups according to the presence of either unilateral, bilateral, or no visual field defects (VFDs). The VFDs occurred irrespective of injury severity as determined by the Glasgow coma scale, or social outcome as determined by the Glasgow outcome scale. Differences among the three visual field groups were obtained for several neuropsychological functions: intelligence, memory, learning, acquired verbal skills, visuospatial skills, and visuomotor speed. Patients with bilateral VFDs were more severely impaired neuropsychologically than those with unilateral or no VFDs. Occurrences of secondary complications (brain swelling, intracranial hypertension, and hyperemia) were more prevalent among the bilateral VFD cases. The findings suggested that bilateral VFDs may be indicators of increased brain damage from secondary insults.This study was supported by NS 08803 from the U.S. National Institute of Neurological Communicative Disorders and Stroke.     

Early seizures after moderate closed head injury

Summary The incidence and clinical significance was studied in 2574 closed head injury patients, each of them having a Glasgow Coma Scale (GCS) 9 to 12 after trauma. All patients underwent computerized tomography (CT) after being admitted to the emergency service. One hundred and six patients (4.1%) experienced seizures within 1 week after head injury; 46 of these (1.8% of the series) had seizures within 24 hours after trauma. There was no statistically significant difference between the early seizure and seizure free group of patients in gender, age and GCS with the exception of cause of injury (p < 0.01). The incidence of intracerebral parenchymal damage was found to be higher with seizures developing between day 2 and day 7 (80%) than those with seizures developing within 24 hours (54.3%). Analysing the data revealed that early posttraumatic seizures were not related to the presence of intracerebral parenchymal damage on CT scan. The occurrence of early seizures did not affect the mortality and outcome of moderate closed head injury patients.     

Primary brain stem haematomas. Diagnosis and treatment

Summary Case histories are reported of 18 patients in whom the diagnosis of primary brain stem haematoma⁵ and brain stem haemorrhage¹³ was made by computed tomography (CT).The possibility of an early diagnosis of brain stem haematoma, and the differential diagnosis of brain stem haemorrhage by a combination of clinical and tomodensitometric criteria is emphasized.It is concluded that CT is a highly reliable method for the diagnosis, location, and management of brain stem haematoma.     

The future role of neurosurgery in the care of head injuries

Summary Head injuries are major cause of death and disability under the age of 45 years even in developing countries. Mortality and morbidity are frequently due to avoidable secondary brain damage in patients whose initial injury was not very severe. Optimal care depends on neurosurgeons defining clear management policies for injuries of all severities so that other surgeons know which patients need neurosurgical care and know how to deal with the others. More patients need to go to neurosurgeons; only specialized centers dealing with many cases can develop advanced clinical skills and have the capability to carry out major clinical research. In the competitive world of high technology medicine neurosurgery needs to deliver good care for head injuries in the community as a whole if it is to attract substantial support.     

Awake stereotactic biopsy of brain stem lesions: technique and results

Summary Background. Brain stem lesions are a heterogenous pathological group. In adults, pre-operative radiological diagnoses prove to be wrong in 10 to 20% of cases. It is therefore imperative to have a tissue diagnosis for appropriate therapeutic measures. Unless these lesions have a sizeable exophytic component, open biopsy and/or resection is marred by low diagnostic yield and prohibitive mortality/morbidity rates.Methods. We describe our experience with awake stereotactic biopsy of brain stem lesions. Keeping the patient awake and monitoring clinically during the procedure allows us to make necessary changes in the trajectory of the biopsy probe to minimize the morbidity. A series of 13 brain stem lesions were stereotactically biopsied using CT guidance. Seven had midbrain lesions; four had pontine and two had Ponto-medullary lesions. A frontal, pre-coronal, transcortical trajectory was used in all patients.Findings. Histological diagnosis was established in all but one patient. There was no procedural mortality, and morbidity was minimal and temporary, occurring in three patients.Conclusion. Awake stereotactic biopsy is a safe technique when combined with clinical monitoring.     

Relative risk of deterioration after mild closed head injury

Summary In this prospective study, a series of 1812 consecutive mild head injured adult patients who visited the hospital emergency department were assessed. Twenty-eight patients (1.5%) deteriorated after head injury; 23 of these (1.3% of the series) required surgical intervention. Five patients (0.3%) deteriorated due to non-surgical causes [post-traumatic seizure 2, syndrome of inapproapriate secretion of antidiuretic hormone (SIADH) 3]. Most of the deterioration occurred within the first 24 hours (57%). Post-traumatic headache was found in 280 patients (15.5%) and 84 patients (4.6%) suffered post-traumatic vomiting.The relative risk is calculated. Age over 60, presence of drowsiness, focal motor weakness, post-traumatic headache and vomiting has increased risk of deterioration (p < 0.001). This study suggests that post-traumatic headache and vomiting deserve more clinical attention rather than being considered as post-traumatic syndrome only.     

Penetrating ballistic-like frontal brain injury caused by a metallic rod

Summary  Penetrating non-missile intracranial injuries caused by metallic foreign bodies are very rare among the civilian population. We present a unique instance of a severe, high-energy, penetrating orbitocranial injury caused by a solid metallic rod that corresponded to the spray valve lever handle of a kitchen sink pre-rinse spray tap, which was fractured and projected at high speed for an unknown reason. To our knowledge, this is the first report of a high-energy, penetrating brain injury caused by such an object. After careful radiological evaluation of the shape and position of the foreign object, a combined right frontal craniotomy and supraorbital osteotomy was performed in order to achieve safe removal of the metal bar. Successful surgical treatment of an orbitocranial injury caused by a similar object has not previously been reported.