Anatomical position of the asterion and its underlying structure.

Surface anatomy is important for surgical planning. The asterion has been believed and used for locating the underlying posterior fossa dura. To prove whether this landmark is reliable or not, forty-three fixed heads of cadaver were dissected. A burr hole was made on the asterion and its underlying structure was examined. Seventy-four point four per cent (74.4%) of the asterion on the right side were adjacent to the transverse-sigmoid sinus complex when compared to 58.1 per cent on the left. Twenty-three point three per cent (23.3%) of the asterion on the right side were found over the infratentorial dura while that on the left side were 32.6 per cent. Two point three per cent (2.3%) of the asterion were located over the supratentorial dura on the right and 9.3 per cent on the left side. It is concluded, therefore, that the asterion is not an appropriate landmark to locate the underlying posterior fossa dura.

The changing pattern of head injury in Thailand.

OBJECTIVE: To determine whether patterns of head injury are changing with time. MATERIALS AND METHODS: A total of 3194 and 4217 consecutive trauma patients who attended the emergency room in 1985-86 and 1996 respectively were studied with respect to age, sex, cause of injury, injury severity, pathology, and outcome. RESULTS: The number of patients with head injury in 1996 nearly doubled (1224/4,217:29.03%) when compared to the 1985-86 study (504/3, 194; 15.78%). This was due to an increase in the outpatient subgroup (1009/1224). The admitted patients with head injury showed a pattern of less severe injury. Severe head injury decreased from 12.4 to 7. 9%. However, acute subdural haematoma and diffuse brain injury increased from 12.2% and 9% to 32% and 16.8% respectively. The mortality rate of admitted patients increased statistically significantly from 14.4% to 21.8% between the 1985-86 and 1996 studies. CONCLUSIONS: This comparative study showed attend toward less severe injury. This may be due to multiple factors. The predominant factor may be the compulsory use of motorcycle helmets. The limitation of this study was that it utilised tertiary hospital based data only. Tertiary hospital receive more and serious head injured patients from surrounding provincial hospitals this may be the major cause of the increased the mortality rate.

Intraoperative intracranial aneurysm rupture.

119 patients with surgically treated intracranial aneurysm between December 18, 1984 and October 1997 were analyzed resulting in nine patients with intraoperative aneurysm rupture. These nine cases formed the basis of this study. The incidence of intraoperative aneurysm rupture was 7.6 per cent. The mortality was 33.3 per cent. In our institution, maneuvers used to control profuse hemorrhage include induced hypotension, suction dissection, and temporary clips at the parent vessels. Some controversies exist regarding the effect of timing of surgery on intraoperative aneurysm rupture and ischemic consequence from induced hypotension. The argument is whether early surgery, within 72 hours, increases the incidence of intraoperative aneurysm rupture.

Nonshaved cranial neurosurgery.

BACKGROUND: Preoperative shaving for cranial neurosurgical procedures is still recommended in textbooks. There are reports demonstrating the success of nonshaved surgery. The objective of this study was to compare the surgical infection rate of cranial neurosurgical procedures with two different scalp preparations: shaved or nonshaved. METHODS: Clinical trials of nonshaved scalp preparation were performed in non-emergency cranial neurosurgical procedures at Songklanagarind Hospital from August 1994 to December 1996. Patients were entered in the nonshaved group using the following exclusion criteria: immunocompromised host, presence of infectious diseases, surgery with foreign material insertion, multiple operations within 1 month, and presence of traumatic wound around the operative site. Patients who survived less than 1 month after surgery were excluded except in cases where death resulted from intracranial infection. RESULTS: During the 29-month period, 225 of 1,244 cranial neurosurgical procedures were selected for study. Ages ranged from 4 to 86 years. Brain tumors were encountered in 57%. In the nonshaved group, there were 89 procedures (80 cases), compared with 136 procedures (123 cases) in the shaved group. Surgical infection rates were 3.37% and 5.88%, respectively (p>0.05). CONCLUSIONS: Nonshaved scalp preparation is recommended for nonemergency cranial neurosurgical procedures.

Anatomical landmark for internal jugular vein catheterization for detection of jugular venous O2 saturation (SjvO2) in Thai people.

Thirty-two (32) cadavers were dissected to find the anatomical landmark for puncturing the internal jugular vein. The point for the right internal jugular vein was 2 cm above and 2.17 cm lateral to the right clavicular head, and that for the left internal jugular vein was 2 cm above and 2.08 cm lateral to the left clavicular head. The right internal jugular vein was found to dominate eighty-eight per cent (88%) of the cadavers. The anatomical point 2 cm above and 2 cm lateral to the head of the clavicle was appropriate for puncturing the internal jugular vein. After puncturing the internal jugular vein, a catheter was inserted ascending to the jugular bulb where jugular venous O2 saturation (Sjv O2) related to the cerebral metabolism was detected.

Endoscopic third ventriculostomy.

We prospectively studied 8 patients who had an endoscopic third ventriculostomy performed between 1996 and 1997 in Songkhlanagarind Hospital. The surgical technique was described. Seven operations were successful and one operation failed. Success was found in cases of pure aqueductal stenosis, aqueductal stenosis with Dandy Walker malformation, and posterior fossa tumor. In a patient where an endoscopic third ventriculostomy failed, aqueductal stenosis with marked hydrocephalus was found. Marked dilation of the third ventricle could compress the aqueduct of Sylvius. Although there was communicating hydrocephalus, it looked like non-communicating hydrocephalus. To avoid a valvular shunting complication, we suggest performance of an endoscopic third ventriculostomy in selected non-communicating hydrocephalus patients.

Post-traumatic hydrocephalus: experience in 17 consecutive cases.

BACKGROUND: Ventriculomegaly after head injury is one of controversial debate. Currently there is no definite way to distinguish post-traumatic hydrocephalus (PTH) from cerebral atrophy. The favourable outcome is only from CSF shunting in patients with true post-traumatic hydrocephalus, not hydrocephalus exvacuo. METHOD: 17 patients with post-traumatic hydrocephalus were retrospectively reviewed from January 1993 to February 1996 to determine risk factors and guidelines for the management of this problem. RESULTS: These 17 patients represented 1.6 per cent of the 1080 head-injured patients seen at Songklanagarind Hospital during that period. 385 patients were classified as severe head injury in whom 7 were complicated with post-traumatic hydrocephalus. Our study found a high incidence of correlation between PTH and decompressive craniectomy. The late effect of decompressive craniectomy may cause CSF blockage around the convexities and hydrocephalus. The diagnoses were based on clinical manifestations and CT scan appearances. The outcome was related closely to the initial GCS score and the method used for diagnosis. CONCLUSION: Post-traumatic hydrocephalus was 1.8 per cent in patients with severe head injury. Late neurological deterioration confirmed by CT scan findings was more useful than CT scan findings alone. CSF shunting was effective in patients with ventriculomegaly who had clinical signs and symptoms of increased intracranial pressure from post-traumatic hydrocephalus.

Traumatic hematomas of the posterior cranial fossa.

The objective of this study was to find out the result of treatment and the factors which can predict the outcome of traumatic hematomas of the posterior cranial fossa. Twenty two patients with traumatic hematomas of the posterior cranial fossa from 1,500 patients with traumatic intracranial hematomas were analyzed. There were fourteen male and eight female patients. The most common etiology was a motor vehicle accident. About 90 per cent of the patients had a direct injury to the occipital region. Ninety per cent of the patients had an occipital skull fracture or diastatic fracture of the lambdoid suture. The overall mortality rate was about 38 per cent. Patients having pure epidural hematoma had zero mortality. By contrast, patients suffering epidural hematoma with associated intracranial hematoma had 20 per cent mortality. Intracerebellar hematoma led to 60 per cent mortality. Glasgow Coma Scale (GCS) before operation was used to predict the patients' outcome. Ninety per cent of the patients who had a GCS between 13 and 15 had a good recovery. By contrast, only 30 per cent of the patients who had a GCS below 9 had a good recovery. Statistical analysis showed that the GCS value of below 9 predicted the poor outcome for the patients.

Multiple intracranial aneurysms in Songklanagarind Hospital.

We retrospectively reviewed the 107 patients on whom direct surgery was performed for intracranial aneurysms between December 18, 1984 and July 25, 1996. The incidence of multiple intracranial aneurysms in our hospital is 6.5 per cent (7/107 cases). There were 16 aneurysms in 7 cases with multiple aneurysms. There were 2 and 5 patients with 3 and 2 aneurysms respectively. The most common site was at the junction of posterior communicating artery (PCoA) and internal carotid artery (ICA). The preoperative conditions of the patients were closely related to the operative results. We performed direct surgery on bilateral aneurysms by bifrontal approaches. There was no mortality.