Survival with good outcome after cerebral herniation and Duret hemorrhage caused by traumatic brain injury

Electrophysiological characteristics of CM-pf in diagnosis and outcome of patients with disorders of consciousness

BACKGROUND

Deep brain stimulation (DBS) in the centromedian-parafascicular complex (CM-pf) has been reported as a potential therapeutic option for disorders of consciousness (DoC). However, the lack of understanding of its electrophysiological characteristics limits the improvement of therapeutic effect.

OBJECTIVE

To investigate the CM-pf electrophysiological characteristics underlying disorders of consciousness (DoC) and its recovery.

METHODS

We collected the CM-pf electrophysiological signals from 23 DoC patients who underwent central thalamus DBS (CT-DBS) surgery. Five typical electrophysiological features were extracted, including neuronal firing properties, multiunit activity (MUA) properties, signal stability, spike-MUA synchronization strength (syncMUA), and the background noise level. Their correlations with the consciousness level, the outcome, and the primary clinical factors of DoC were analyzed.

RESULTS

11 out of 23 patients (0/2 chronic coma, 5/13 unresponsive wakefulness syndrome/vegetative state (UWS/VS), 6/8 minimally conscious state minus (MCS-)) exhibited an improvement in the level of consciousness after CT-DBS. In CM-pf, significantly stronger gamma band syncMUA strength and alpha band normalized MUA power were found in MCS- patients. In addition, higher firing rates, stronger high-gamma band MUA power and alpha band normalized power, and more stable theta oscillation were correlated with better outcomes. Besides, we also identified electrophysiological properties that are correlated with clinical factors, including etiologies, age, and duration of DoC.

CONCLUSION

We provide comprehensive analyses of the electrophysiological characteristics of CM-pf in DoC patients. Our results support the 'mesocircuit' hypothesis, one proposed mechanism of DoC recovery, and reveal CM-pf electrophysiological features that are crucial for understanding the pathogenesis of DoC, predicting its recovery, and explaining the effect of clinical factors on DoC.

Recovery from disorders of consciousness: mechanisms, prognosis and emerging therapies

Substantial progress has been made over the past two decades in detecting, predicting and promoting recovery of consciousness in patients with disorders of consciousness (DoC) caused by severe brain injuries. Advanced neuroimaging and electrophysiological techniques have revealed new insights into the biological mechanisms underlying recovery of consciousness and have enabled the identification of preserved brain networks in patients who seem unresponsive, thus raising hope for more accurate diagnosis and prognosis. Emerging evidence suggests that covert consciousness, or cognitive motor dissociation (CMD), is present in up to 15-20% of patients with DoC and that detection of CMD in the intensive care unit can predict functional recovery at 1 year post injury. Although fundamental questions remain about which patients with DoC have the potential for recovery, novel pharmacological and electrophysiological therapies have shown the potential to reactivate injured neural networks and promote re-emergence of consciousness. In this Review, we focus on mechanisms of recovery from DoC in the acute and subacute-to-chronic stages, and we discuss recent progress in detecting and predicting recovery of consciousness. We also describe the developments in pharmacological and electrophysiological therapies that are creating new opportunities to improve the lives of patients with DoC.

Duret Hemorrhage after Extradural Hematoma Evacuation–A Rare Entity

Traumatic brainstem injury can be classified as primary or secondary. Secondary brainstem hemorrhage that evolves from raised intracranial pressure (ICP) and transtentorial herniation is referred to as Duret hemorrhage. We report a 25-year-old male who underwent emergency craniotomy, with evacuation of acute epidural hematoma, and postoperatively developed fatal Duret hemorrhage. Duret hemorrhage after acute epidural hematoma (EDH) evacuation is a very rare complication and the outcome is grave in most of the cases.

Recovery of Functional Independence After Traumatic Transtentorial Herniation With Duret Hemorrhages

Historically, Duret hemorrhages have conferred a devastating prognosis. However, recent case reports suggest that cognitive and functional recovery are possible after Duret hemorrhages. Here, we describe a patient who recovered consciousness, communication, and functional independence after Duret hemorrhages caused by traumatic transtentorial herniation. We performed prospective, standardized behavioral assessments, structural MRI scans and stimulus-based functional MRI (fMRI) scans during the first 2 years of recovery. The multimodal assessments revealed reintegration of neural networks mediating language and consciousness, concurrent with the reemergence of functional independence. These observations provide insights into network-based mechanisms of recovery from coma and add to a growing body of evidence indicating that Duret hemorrhages are not invariably associated with a poor prognosis.

Noninvasive assessment of hemodynamic and brain metabolism parameters following closed head injury in a mouse model by comparative diffuse optical reflectance approaches

Optical techniques have gained substantial interest over the past four decades for biomedical imaging due to their unique advantages, which may suggest their use as alternatives to conventional methodologies. Several optical techniques have been successfully adapted to clinical practice and biomedical research to monitor tissue structure and function in both humans and animal models. This paper reviews the analysis of the optical properties of brain tissue in the wavelength range between 500 and 1000 nm by three different diffuse optical reflectance methods: spatially modulated illumination, orthogonal diffuse light spectroscopy, and dual-wavelength laser speckle imaging, to monitor changes in brain tissue morphology, chromophore content, and metabolism following head injury. After induction of closed head injury upon anesthetized mice by weight-drop method, significant changes in hemoglobin oxygen saturation, blood flow, and metabolism were readily detectible by all three optical setups, up to 1 h post-trauma. Furthermore, the experimental results clearly demonstrate the feasibility and reliability of the three methodologies, and the differences between the system performances and capabilities are also discussed. The long-term goal of this line of study is to combine these optical systems to study brain pathophysiology in high spatiotemporal resolution using additional models of brain trauma. Such combined use of complementary algorithms should fill the gaps in each system's capabilities, toward the development of a noninvasive, quantitative tool to expand our knowledge of the principles underlying brain function following trauma, and to monitor the efficacy of therapeutic interventions in the clinic.

Good outcomes in a patient with a Duret hemorrhage from an acute subdural hematoma

Background

Secondary brain stem injury is associated with transtentorial herniation, and manifests as “Duret” hemorrhages. Such an injury has been considered a terminal brain stem event with a high morbidity and mortality, sometimes discouraging continuation of care. However, there have been rare instances where patients have had reasonable recovery. We report another case, emphasizing that such an injury by itself should not deter aggressive measures, as good outcomes remain a possibility.

Case presentation

A 37-year-old male sustained a right subdural hematoma after a mechanical fall while intoxicated. He presented initially with a Glasgow Coma Scale 15. Three days later, he exhibited acute neurological deterioration to Glasgow Coma Scale 4, requiring intubation and mannitol. Repeat scan demonstrated enlarging right subdural hematoma with worsening shift; brain stem hemorrhage was noted at pontomesencephalic junction. Patient was immediately taken for subdural hematoma evacuation. The following day, patient was able to sluggishly follow commands in all four extremities. He had a short stay for inpatient rehabilitation and underwent autologous cranioplasty at 3 months. On examination, he was awake, alert, and oriented to self, time, and location; he exhibited dysarthric speech, right ptosis, but followed commands in all four extremities with no focal motor weakness.

Conclusion

In contrast to the common belief, patients suffering from a “Duret” hemorrhage can still have a good outcome. “Duret” hemorrhages may not represent a fatal injury. The finding from this paper suggests the finding of “Duret” hemorrhages on imaging should not deter aggressive measures especially in patients with lesions causing significant mass effects. Overall clinical status should drive surgical options and clinical course.

Reversible coma and Duret hemorrhage after intracranial hypotension from remote lumbar spine surgery: case report

Intracranial hypotension is a rare condition caused by spontaneous or iatrogenic CSF leaks that alter normal CSF dynamics. Symptoms range from mild headaches to transtentorial herniation, coma, and death. Duret hemorrhages have been reported to occur in some patients with this condition and are traditionally believed to be associated with a poor neurological outcome. A 73-year-old man with a remote history of spinal fusion presented with syncope and was found to have small subdural hematomas on head CT studies. He was managed nonoperatively and discharged with a Glasgow Coma Scale score of 15, only to return 3 days later with obtundation, fixed downward gaze, anisocoria, and absent cranial nerve reflexes. A CT scan showed Duret hemorrhages and subtle enlargement of the subdural hematomas, though the hematomas remained too small to account for his poor clinical condition. Magnetic resonance imaging of the spine revealed a large lumbar pseudomeningocele in the area of prior fusion. His condition dramatically improved when he was placed in the Trendelenburg position and underwent repair of the pseudomeningocele. He was kept flat for 7 days and was ultimately discharged in good condition. On long-term follow-up, his only identifiable deficit was diplopia due to an internuclear ophthalmoplegia. Intracranial hypotension is a rare condition that can cause profound morbidity, including tonsillar herniation and brainstem hemorrhage. With proper identification and treatment of the CSF leak, patients can make functional recoveries.

Descending transtentorial herniation, a rare complication of the treatment of trapped fourth ventricle: case report

Descending transtentorial herniation (DTH) is a complication of raised pressure in the supratentorial compartment, usually resulting from mass lesion of several etiologies. The authors report an exceptional case of DTH complicating the implant of a CSF shunting device in the trapped fourth ventricle of a 17-year-old boy in whom a second CSF shunting device had been implanted for neonatal posthemorrhagic and postinfectious hydrocephalus. The insidious clinical and radiological presentation of DTH, mimicking a malfunction of the supratentorial shunt, is documented. Ultimately, the treatment consisted of removal of the infratentorial shunt and endoscopic acqueductoplasty with stenting. The absence of supratentorial mass lesion and other described etiologies of DTH prompted the authors to speculate on the hydrodynamic pathogenesis of DTH in the present case.

Pediatric brainstem hemorrhages after traumatic brain injury

Traumatic brain injuries afflict a large number of pediatric patients. The most severe injuries lead to increased intracranial pressure and herniation, with resultant changes in the brainstem. Traumatic brainstem hemorrhages have previously been associated with poor neurological outcome and fatality. However, this report discusses 2 pediatric patients who sustained severe head trauma with subsequent brainstem hemorrhages, and yet experienced good neurological outcome; the possible mechanism is described.

Management of intracerebral pressure in the neurosciences critical care unit

Management of intracranial pressure in neurocritical care remains a potentially valuable target for improvements in therapy and patient outcomes. Surrogate markers of increased intracranial pressure, invasive monitors, and standard therapy, as well as promising new approaches to improve cerebral compliance are discussed, and a current review of the literature addressing this metric in neuroscience critical care is provided.

Precedence of Parenchymal Enhancement on CT Angiography to a Fatal Duret Hemorrhage

We report a case of fatal duret hemorrhage (DH) in a patient with acute tentorial subdural hematoma and bilateral chronic subdural hematoma along the cerebral hemispheres. Preoperative CT angiography (CTA) revealed prominent parenchymal enhancement in the ventral pontomesencephalic area. After burr-hole drainage, a large hemorrhage developed in this area. The parenchymal enhancement in the CTA may reflect the pontomensencephalic perforating vessel injury, and may be a sign of impending DH of acute transtentorial downward herniation. Previous use of aspirin and warfarin might have potentiated the process of DH and increase the extent of the bleed.

Emergency radiology eponyms: part 1-Pott's puffy tumor to Kerley B lines

An eponym is a name based on the name of a person, frequently as a means to honor him/her, and it can be used to concisely communicate or summarize a complex abnormality or injury. However, inappropriate use of an eponym may lead to potentially dangerous miscommunication. Moreover, an eponym may honor the incorrect person or a person who falls into disrepute. Despite their limitations, eponyms are still widespread in medicine. Many commonly used eponyms applied to extremity fractures should be familiar to most emergency radiologists and have been previously reported. Yet, a number of non-extremity eponyms can be encountered in an emergency radiology practice as well. This other group of eponyms encompasses a spectrum of traumatic and non-traumatic pathology. In this first part of a two-part series, the authors discuss a number of non-extremity emergency radiology eponyms, including relevant clinical and imaging features, as well biographical information of the eponyms' namesakes.

Bilateral hemicraniectomy in non-penetrating traumatic brain injury

Traumatic brain injury is a heterogeneous entity that encompasses both surgical and non-surgical conditions. Surgery may be indicated with traumatic lesions such as hemorrhage, fractures, or malignant cerebral edema. However, the neurological exam may be clouded by the effects of medications administered in the field, systemic injuries, and inaccuracies in hyperacute prognostication. Typically, neurological injury is considered irreversible if diffuse loss of grey/white matter differentiation or if brainstem hemorrhage (Duret hemorrhage) exists. We aim to characterize a cohort of patients undergoing bilateral hemicraniectomy for severe traumatic brain injury. A retrospective consecutive cohort of adult patients undergoing craniectomy for trauma was established between the dates of January 2008 and November 2011. The primary outcome of the study was in-hospital mortality. Secondary outcomes were ICU length of stay, surgical complications, and Glasgow Outcome Score at most recent follow-up. During the study period, 210 patients undergoing craniectomy for traumatic mass-occupying lesion (epidural hematoma, subdural hematoma, or parenchymal contusion) were analyzed. Of those, 9 met study criteria. In-hospital mortality was 67% (6 of 9 patients). The average ICU length of stay was 12 days. The GOS score was 3 in surviving patients. Bilateral hemicraniectomy is a heroic intervention for patients with severe TBI, but can be a life-saving procedure.