Familial ossification of the stylohyoid ligament in a three generation family--a new clinical entity displaying autosomal dominant inheritance.

Ossification of the stylohyoid ligament is very common in the Caucasian population. More than 9000 descriptions of apparently isolated case reports on PubMed have been cited over the last 20 years, often associated with an incidental finding on imaging after neck trauma. No cases of familial ossification have been described. We document a family with several affected members, each with an ossified stylohyoid ligament, confirming that ossification may be hereditary in some families and is most likely due to an autosomal dominant gene.

The role of specialist neuroradiology second opinion reporting: is there added value?

AIM: To assess the impact on patient management of formal neuroradiology "second reading" of computed tomography (CT) and magnetic resonance imaging (MRI) images initially interpreted by general radiologists. MATERIALS AND METHODS: Second opinion reports during the calendar year 2004 were compared with the original report and assessed for major or minor discrepancies. A major discrepancy was separated from a minor discrepancy whereby a change in opinion significantly affected patient management. RESULTS: There were 506 second opinions during 2004 given by three consultant neuroradiologists. Incomplete data were found in 141. Forty-one percent were CT images and the remainder MRI. The majority of second opinions were requested by neurologists. Most of the remaining referrals were from neurosurgeons or the primary radiologist. There was a 13% major and a 21% minor discrepancy rate. The remaining 66% were in complete agreement. There was a mixture of overcalls, misinterpretation, and undercalls. There were similar rates of minor and major discrepancies in both CT and MRI. CONCLUSION: There is a significant major discrepancy rate between specialist neuroradiology second opinion and general radiologists. The benefit of a formal specialist second opinion service is clearly demonstrated; however, it is time-consuming.

Posterior fossa arachnoid cyst presenting with unilateral tremor.

A rare case of unilateral benign essential tremor is presented that responded to surgical excision of a posterior fossa arachnoid cyst.

Unusual stab injury of the spinal cord.

OBJECTIVE: To report an unusual penetrating stab injury of the spinal cord. DESIGN: Case report of a 13-year-old boy who sustained cervical trauma following an accident while playing. SETTING: Spinal Cord Injuries Unit, Musgrave Park Hospital, Belfast, UK. CASE REPORT: Mechanism of injury was by a spear-like electric fence post entering the neck. Initial neurological examination revealed tetraplegia with C4 sensory level. Magnetic resonance imaging (MRI) of spinal cord demonstrates the penetrating injury. CONCLUSION: No ligamentous instability was demonstrated. In the absence of this, the penetrating injury by a short blade thrown at speed was felt to be responsible for the subsequent injury and resulting outcome at discharge of C4 American Spinal Injury Association (ASIA) grade D tetraplegia.

Absorbed dose and deterministic effects to patients from interventional neuroradiology.

Following the presentation of radiation-induced skin effects by three patients who had undergone glue embolisation of intracranial arteriovenous malformation (AVM), measurements were made of absorbed dose to the skin of patients undergoing other interventional neuroradiological procedures that involve long fluoroscopy times. The maximum absorbed dose to the skin measured by thermoluminescent dosemeters during these procedures was 4 Gy. From these measurements and from records of fluoroscopy time and the number of digital runs acquired, estimates of the maximum absorbed skin dose were made for the AVM patients. The best estimate of maximum absorbed dose to the skin received by any of the AVM patients during a procedure was 5 Gy, which is consistent with the skin effects presented by the AVM patients, that is temporary epilation and main erythema. Maximum absorbed dose to the skull was estimated to be 45 Gy and to the outer table of the skull 55 Gy. Although it is unlikely that the AVM patients will suffer serious effects from these skin doses, there remains some uncertainty over the risk of long-term effects to the skull. Examination of the fluoroscopy unit showed that the image intensifier was not performing optimally in terms of entrance dose rate and resolution. Replacement of the unit with modern X-ray equipment designed for interventional radiology was prioritized. Operators should be aware of the potential risks to patients from complex interventional neuroradiology procedures and should optimize their procedures to minimize such risks. Patients undergoing prolonged and complex procedures should be counselled regarding the symptoms and risks of large doses of radiation.

Bilateral astrocytoma involving the limbic system precipitating disabling amnesia and seizures.

Astrocytomas involving the limbic system are usually unilateral in nature. We report a very unusual case where a low-grade astrocytoma originating in the left temporal lobe spread to the right hippocampus through the hippocampal commissure to cause disabling amnesia and seizures. Some improvement in the memory deficit was facilitated by identification of complex partial status epilepticus. EEG should be performed in all patients with lesions of the limbic system and neuropsychological problems if ongoing seizure activity is not to be missed.

Neuroradiological history: Sir Joseph Larmor and the basis of MRI physics.

The origin of many of the eponymous terms in modern medicine is unknown to many people who utter them daily. As a contribution to understanding the historical background of MRI, we provide a brief account of the life and work of Joseph Larmor, the Irish scientist, whose name is frequently used by chemists, physicists and radiologists alike.

Arteriovenous fistula after temporomandibular arthroscopy.

Temporomandibular joint arthroscopy has been associated with various vascular injuries including haemorrhage, pseudoaneurysm and fistula. We describe the endovascular balloon embolization of a traumatic superficial temporal arteriovenous fistula that complicated TMJ arthroscopy. We conclude that suspected vascular injuries after this procedure should be investigated by arteriography, and that embolization is a safe and effective treatment for superficial temporal artery fistulas.

An evaluation of how MRI is used as a pre-operative screening investigation in patients with temporal lobe epilepsy.

AIMS: A retrospective analysis was carried out of how magnetic resonance imaging (MRI) is used as a pre-operative screening investigation in patients with a clinical diagnosis of medically intractable temporal lobe epilepsy (TLE). Up to 65% of such patients are said to have hippocampal sclerosis (HS). MATERIALS AND METHODS: Forty-six patients in a 26-month period underwent MR examination on a 1.5 T scanner according to a routine protocol. Each patient had coronal T1-weighted and oblique coronal T2-weighted scans performed. Hippocampal volume was calculated from the T1-weighted images, the T2-weighted images being assessed for relative hippocampal signal intensity. Each individual patient's medical records were audited. RESULTS: Thirty per cent of patients in our study had a diagnosis of HS made on their MR scan. No patient had a diagnosis of HS made without prior clinical evidence of seizure lateralization. Sixty-eight per cent of patients with clinical evidence of a unilateral seizure focus had HS diagnosed by MR scanning. Forty-three per cent of patients did not have clinical evidence of an unilateral seizure focus. It was found that over 25% of patients referred to the unit did not fit the criteria of having medically intractable TLE. Nine per cent of patients had previously stated that they did not want epilepsy surgery. CONCLUSION: The lower than expected diagnostic rate of HS in this patient population reflects the broad criteria used in referring patients for imaging studies. This is likely to mirror the initial investigation of these patients outside specialist units where more extensive investigation prior to MRI is available. However, when MRI is used as an initial screening investigation, this study indicates that implementation of simple clinical criteria should significantly reduce the number of unnecessary scans.

Guidelines for lumbar spine radiography in acute low back pain: effect of implementation in an accident and emergency department.

Guidelines for lumbar spine radiography were agreed by consultation between staff in the radiology, accident and emergency and neurosurgical departments of a large teaching hospital. Study of 322 consecutive patients over an eight month period showed that the proportion of patients referred for radiography was reduced from 48.4% to 27.2% following introduction of the guidelines (p = 0.0002). Successful use of such guidelines requires cooperation between clinical and radiological staff and frequent review of performance.

The value of repeat cerebral angiography in subarachnoid haemorrhage.

In 216 consecutive patients investigated for subarachnoid haemorrhage, 44 (20.3%) of cerebral angiograms were either normal or equivocal for the presence of aneurysm. Arteriography was repeated in 30 patients and an aneurysm was demonstrated in 10 cases. Repeat arteriography is recommended in proven subarachnoid haemorrhage even when the initial study is normal, and in this study achieved a reduction in overall negative rate to 15.6%.