Ahmed-Ramadan Sadek

Spontaneous upper limb monoplegia secondary to probable cerebral amyloid angiopathy

Cerebral amyloid angiopathy is a clinicopathological disorder characterised by vascular amyloid deposition initially in leptomeningeal and neocortical vessels, and later affecting cortical and subcortical regions. The presence of amyloid within the walls of these vessels leads to a propensity for primary intracerebral haemorrhage. We report the unusual case of a 77-year-old female who presented to our emergency department with sudden onset isolated hypoaesthesia and right upper limb monoplegia. A CT scan demonstrated a peripheral acute haematoma involving the left perirolandic cortices. Subsequent magnetic resonance imaging demonstrated previous superficial haemorrhagic events. One week following discharge the patient re-attended with multiple short-lived episodes of aphasia and jerking of the right upper limb. Further imaging demonstrated oedematous changes around the previous haemorrhagic insult. Cerebral amyloid angiopathy is an overlooked cause of intracerebral haemorrhage; the isolated nature of the neurological deficit in this case illustrates the many guises in which it can present.

Polarized distribution of AMPA, but not GABAA , receptors in radial glia-like cells of the adult dentate gyrus.

Glial fibrillary acidic protein (GFAP)‐positive astrocytes with radial processes [radial glia (RG)‐like cells] in the postnatal dentate gyrus share many of the characteristics of embryonic radial glia and appear to act as precursor cells for adult dentate neurogenesis, a process important for pattern separation and hippocampus‐dependent learning. Although much work has delineated the mechanisms underlying activity‐neurogenesis coupling via gamma‐amino butyric acid (GABA)ergic neurotransmission on GFAP‐negative transient‐amplifying cells and neuroblasts, little is known regarding the effects of neurotransmitters on RG‐like cells. Conflicting evidence exists for both GABA and glutamate receptors on these cells. Here, using GFAP reporter mice, we show that the somatic membrane of RG‐like cells carries GABAA receptors and glutamate transporters but not ionotropic glutamate receptors, whereas 2‐amino‐3‐(hydroxyl‐5‐methylisoxazole‐4‐yl) propionic acid (AMPA) and GABAA receptors are expressed on the processes of these cells. Almost all RG‐like cells expressed the GluA2 subunit, which restricts the Ca2+ permeability of AMPA receptors. The glial GABAA receptors mainly comprised α2/α4, β1, and γ1/γ3. The selective presence of AMPA receptors on the radial processes may be important for sensing and responding to local activity‐driven glutamate release and supports the concept that RG‐like astrocytes are composed of functional and structural domains.

Seizure-induced miosis

Ictal autonomic pupillary dilation is common; however, miosis is rare. We describe a case of focal seizures secondary to cortical dysplasia presenting with bilateral pupillary miosis, rendered seizure free by resective surgery. The seizure‐onset zone was localized within the left middle parietal gyrus by intracranial electrographic recording. Seizure onset was coincident with focal left centroparietal fast spike activity on electroencephalography (EEG). A large region of the left frontocentral cortical dysplasia was demonstrated on magnetic resonance imaging (MRI). Complete resection of the area of cortical dysplasia and additional cortical regions of ictal activity, identified using intracranial EEG, rendered the patient seizure free.

Electroconvulsive therapy: A novel hypothesis for the involvement of purinergic signalling

It is proposed that ATP is released from both neurons and glia during electroconvulsive therapy (ECT) and that this leads to reduction of depressive behaviour via complex stimulation of neurons and glia directly via P2X and P2Y receptors and also via P1 receptors after extracellular breakdown of ATP to adenosine. In particular, A1 adenosine receptors inhibit release of excitatory transmitters, and A2A and P2Y receptors may modulate the release of dopamine. Sequential ECT may lead to changes in purinoceptor expression in mesolimbic and mesocortical regions of the brain implicated in depression and other mood disorders. In particular, increased expression of P2X7 receptors on glial cells would lead to increased release of cytokines, chemokines and neurotrophins. In summary, we suggest that ATP release following ECT involves neurons, glial cells and neuron–glial interactions acting via both P2 and after breakdown to adenosine via P1 receptors. We suggest that ecto-nucleotidase inhibitors (increasing available amounts of ATP) and purinoceptor agonists may enhance the anti-depressive effect of ECT.

Posterior reversible encephalopathy syndrome: a case following reversible cerebral vasoconstriction syndrome masquerading as subarachnoid haemorrhage

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic clinico-radiological diagnosis typically presenting with headache, encephalopathy and visual disturbance accompanied by a unique neuroradiological pattern of symmetrical parieto-occipital vasogenic oedema. Here we present the case of a 51-year-old woman who presented to hospital following a thunderclap headache, initially thought to be secondary to a subarachnoid haemorrhage (SAH). A tiny anterior choroidal artery aneurysm was demonstrated on cerebral angiogram. At surgical clipping, no evidence of haemorrhage was observed. Post-operatively, the patient developed delayed right-sided hemiparesis, managed with aggressive hypertensive treatment, and later, with onset of septicaemia, central visual loss. Computed tomography (CT) brain scans demonstrated oedematous changes within the parieto-occipital regions bilaterally and later areas of infarction. The initial diagnosis of SAH was revised to reversible cerebral vasoconstriction syndrome (RCVS), which gave rise to PRES. To our knowledge, this is the first reported case of RCVS with concomitant PRES and cerebral infarction.

Emphysematous cystitis with clinical subcutaneous emphysema

Emphysematous cystitis (EC) is the presence of intramural gas, with or without luminal gas, within the bladder as a result of a primary infection of the lower urinary tract with a gas-producing organism. It is a well-recognised complication of urinary tract infections involving Escherichia coli in diabetic patients. Clinical subcutaneous emphysema is a rare complication of EC that appears to have poor prognosis. Only careful clinical judgement, and a high degree of suspicion, will lead to its early diagnosis and treatment. Here, we report a case of subcutaneous emphysema due to EC based on a clinical diagnosis confirmed using computed tomography (CT).

Pituitary apoplexy can mimic acute meningoencephalitis or subarachnoid haemorrhage

Pituitary apoplexy is an uncommon but life-threatening condition that is often overlooked and underdiagnosed. We report a 45-year-old man who presented to our emergency department with a sudden onset headache, acute confusion, signs of meningeal irritation and ophthalmoplegia. An initial diagnosis of acute meningoencephalitis was made, which was amended to pituitary apoplexy following thorough investigation within the emergency department.A 45-year-old man was brought to our emergency department by ambulance with a history of sudden onset of frontal headache and acute confusion. His wife provided the history. There was no significant past medical history of diabetes, hypertension, recent travel abroad, exposure to sick contacts, involvement in outdoor pursuits such as hiking/cave diving, or trauma. He worked in a bank and had been well until 24 h prior to the onset of sudden headache, which was gradually worsening in nature and associated with increasing confusion. The patients wife reported that he had neither experienced any fevers, night sweats, or coryzal symptoms nor received any recent vaccinations. He was not on any regular medications. He was a non-smoker and occasionally consumed alcohol. There was no significant family history. On examination in the ED, his temperature was 37.6°C, his pulse was 110/min, and he was normotensive and normoglycaemic. A macular blanching rash was noted over the patients trunk. The patient was disoriented to time and place. Neurological examination revealed reduced GCS (11/15-E3, M6, V2), marked neck stiffness, a positive Kernigs sign and a right sixth nerve palsy.A provisional diagnosis of acute meningoencephalitis was made and the patient was started on a course of intravenous antibiotics with benzyl penicillin 1.2 g, cefotaxime 2 g and acyclovir 750 mg. Baseline blood investigations revealed hyponatraemia (122 mmol/l), a white-cell count of 11 × 109/l and a C-reactive protein > 250. Due to the sudden onset of the symptoms and lack of prodrome, an urgent CT head scan was performed to rule out a cerebrovascular event. The scan demonstrated an enlarged pituitary gland (3 cm in diameter) with impingement of the optic chiasm. The centre of the enlarged pituitary gland was noted to be hypodense in comparison to its periphery, which was consistent with a diagnosis of pituitary apoplexy. A subsequent MRI confirmed the diagnosis (Figure 1) of an enlarged sella containing abnormal soft tissue with increased signal intensity suggestive of haemorrhage (Figure 1A).Post-MRI a lumbar puncture was performed revealing glucose 3.4 mmol/l, protein 1.0 g/l, red cells of 53/mm3 and white cells of 174/mm3 with predominant neutrophilia. No organisms were seen, and CSF cultures and HSV DNA tests were found to be negative. Endocrinological investigations demonstrated low concentrations of thyroid hormones [TSH: 0.14 mIu/l (0.35-5.5 mlU/l), FT3: 1.1 nmol/l (1.2-3.0 nmol/l), FT4: 9.6 pmol/l (8-22 pmol/l)], gonadal hormones (LH: < 1 u/l) and prolactin: 16 u/l (<450 u/l). Serum FSH was 2.9 u/l (0.8-11.5 u/L) and cortisol 575 nmol/l (450-700 nmol/l). The patient was treated for hypopituitarism based on clinical and radiological findings with intravenous fluids, hydrocortisone (100 mg) and thyroxine (50 μg) as loading doses in the ED.Within 24 h of commencement of therapy the patients GCS rose to 15, and within 48 h there was marked improvement in the right sixth cranial nerve palsy. Formal visual field assessment demonstrated temporal visual field loss in the left eye. The patient was discharged to his usual residence a week later and follow-up was organised with both the endocrinologists and ophthalmologists. Follow-up MRI demonstrated that there was no significant change in either size or signal characteristics of the pituitary fossa mass (Figure 1B).

Idiopathic thoracic intravertebral spinal cord herniation

A 58-year-old man presented with a two-and-a-half year history of painful left L2 to S1 radiculopathy and progressively worsening left quadriceps weakness. On examination he had grade three power i...

Comment on: recurrent subdural hygromas after foramen magnum decompression for Chiari type-1 malformation

It is increasingly apparent that the precise surgical approach for decompression of the foramen magnum to [re]establish normal cerebrospinal flow dynamics in Chiari type-1 malformation (C1M) is more complex than has previously been envisaged. We have read with interest the recently described experiences of Pereira et al. and that of Duddy et al., in your journal on the matter. Our own [unpublished] single-surgeon single-center experience, from 2007 to 2013, we believe adds further to both the discussion and the search for a definitive approach to foramen magnum decompression (FMD) in C1M. A total of 34 FMDs were performed for C1M. Similar to the preoperative algorithms in other centers all cases of raised intracranial pressure were identified by clinical and radiographic evaluation and managed prior to surgery. A standard posterior fossa craniectomy, removal of the arch of C1, removal of the tip of the spinous process of C2, exposure of vertebral artery and hitching of dura to tip of C2 to create a funnel was always performed; however, the remainder of the operative strategy has evolved over the seven-year period. The postoperative outcomes following FMD when viewed independently of the precise surgical strategy have been disappointing, with some outcomes not dissimilar to previously described findings. Only 47% of the cases had an improvement in headaches, this is in contrast to previous studies which report a 90% improvement. Postoperative hydrocephalus requiring ventriculoperitoneal shunting was noted in 17.6% (6/34) of cases which is consistent with findings (6.8% to 18.5%) published most recently in this journal. We observed subdural hygromas in 11.8% (4/34) compared to a reported 3%. Three cases had to undergo a redo FMD with opening of the arachnoid, all of which had subsequent improvement in their symptoms. It is, however, misleading to view these results at face value, it is well understood, although not readily at the forefront of a surgeon’s mind, which heuristics define and result in improvement in the surgical approach over time. In our cohort, following decompression, the arachnoid was left intact and the dura was initially closed with a synthetic dural substitute (duraplasty). Under 40% of cases had improvement in their symptoms with further surgical intervention required in 50% of the cases (Table 1). In light of accepted emerging practice, a decision was made to evolve the approach and open the arachnoid with a view to improving outcomes. Unfortunately, little headway in improving outcome was made with this change (Table 1). Following this, a decision was made to leave the dura open and to tack it to the overlying muscle (durotomy). After no improvement in outcome was noted, when the arachnoid was left intact a decision was made to open the arachnoid and hitch it to the dura (n1⁄4 11). It was only after this change that we noted that over 90% of patients had improvement in their headaches. We did not observe subdural hygromas or hydrocephalus in this subset of our cohort. Despite the obvious limitations of our cohort size, it is evident that the group that underwent a durotomy and opening of the arachnoid did most favorably. It has previously been stipulated that breach or disruption of the arachnoid results in altered flow dynamics with ensuing hydrocephalus and or a subdural hygroma formation. Our findings and those of others suggest that hydrocephalus as result the blockage of the arachnoid villi, after opening the arachnoid, is too simplistic an explanation as hydrocephalus was observed infrequently in cases where the arachnoid was opened in either durotomy or duraplasty (Table 1). Conversely, where the arachnoid was preserved, we noted a higher frequency of hydrocephalus and subdural hygroma formation. Rather, interestingly, we noted that in one of the three cases where the arachnoid was breached inadvertently a further surgical procedure was needed to manage hydrocephalus and evacuation of a subdural hygroma. One may speculate that it is actually this minor alteration in CSF flow dynamics as a result of an inadvertent arachnoid breach that may herald post-operative hydrocephalus and subdural hygroma formation. We hypothesize that elimination of the subdural space by hitching of the arachnoid up to the dura prevents the variation in CSF pressures within the foramen magnum decompression and hence prevents ensuing hydrocephalus and or subdural hygroma formation. It would be highly informative if our colleagues could subclassify their outcomes in their case series on the basis of their surgical approach to clarify whether their findings mirror ours. Although it may be disheartening initially, the ‘gold-standard approach’ can only be identified after appraisal of each putative approach for a single procedure.

Image guidance and improved accuracy of external ventricular drain tip position particularly in patients with small ventricles

OBJECTIVEExternal ventricular drain (EVD) insertion is one of the most common emergency neurosurgical procedures. EVDs are traditionally inserted freehand (FH) in an emergency setting, but often result in suboptimal positioning. Image-guided surgery (IGS) is selectively used to assist placement. However, the accuracy and practicality of IGS use is yet to be reported. In this study, the authors set out to assess if IGS is practical and improves the accuracy of EVD placement.METHODSCase notes and images obtained in patients who underwent frontal EVD placement were retrospectively reviewed. Ventriculomegaly was determined by the measurement of the Evans index. EVD location was classified as optimal (ipsilateral frontal horn) or suboptimal (any other location). Propensity score matching of the two groups (IGS vs FH) for the Evans index was performed. Data were analyzed for patient age, diagnosis, number of EVDs, and complications. Those without postoperative CT scans were excluded.RESULTSA total of 607 patients with 760 EVDs placed were identified; 331 met inclusion criteria. Of these, 287 were inserted FH, and 44 were placed with IGS; 60.6% of all unmatched FH EVDs were optimal compared with 75% of the IGS group (p = 0.067). The IGS group had a significantly smaller Evans index (p < 0.0001). Propensity score matching demonstrated improved optimal position in the IGS group when compared with the matched FH group (75% vs 43.2%, OR 4.6 [1.5-14.6]; p = 0.002). Patients with an Evans index of ≥ 0.36 derived less benefit (75% in IGS vs 66% in FH, p = 0.5), and those with an Evans index < 0.36 derived more benefit (75% in IGS vs 53% in FH, p = 0.024). The overall EVD complication rate was 36% in the FH group versus 18% in the IGS group (p = 0.056). Revision rates were higher in the FH group (p = 0.035), and the operative times were similar (p = 0.69). Long intracranial EVD catheters were associated with tip malposition irrespective of the group.CONCLUSIONSImage guidance is practical and improves the accuracy of EVD placement in patients with small ventricles; thus, it should be considered for these patients.