Recovery of the corticospinal tract after injury by transtentorial herniation: a case report

Little is known about recovery of the corticospinal tract (CST) after injury by transtentorial herniation (TH). We present with a patient who showed recovery of the CST after injury by TH, using diffusion tensor tractography (DTT) and transcranial magnetic stimulation (TMS). A 69-year-old female underwent craniotomy and drainage of an intracerebral hemorrhage in the left corona radiata and basal ganglia. Brain CT showed left TH and brain MRI revealed a leukomalactic lesion at the left cerebral peduncle. The patient presented with complete paralysis of the right extremities at ICH onset, but slowly recovered some function to the point of being able to move the affected extremities against gravity at about 6 months after onset. Three-week DTT showed disruption of the left CST below the cerebral peduncle; however, this disruption was recovered on 1-year DTT. Three-week TMS showed no motor evoked potential for the affected hemisphere; in contrast, motor evoked potentials that were compatible with regenerated CST were obtained from the affected hand muscle at 6 months. Using DTT and TMS in a patient with ICH, we demonstrated recovery of the CST after injury by TH.     

Kernohan-Woltman notch phenomenon caused by an acute subdural hematoma

Uncal herniation through the tentorial notch is occasionally associated with false localizing ipsilateral hemiparesis, known as the Kernohan-Woltman notch phenomenon (KWNP). We report an 81-year-old female who presented with a decreased level of consciousness, a right mydriasis and an ipsilateral motor deficit caused by a large right hemispheric subdural hematoma that was immediately evacuated. The patient recovered well, although her right hemiplegia persisted. A follow-up MRI showed a residual lesion in the left cerebral peduncle, corresponding to KWNP. The presence of such a structural lesion suggests a poor prognosis for recovery from the initial motor deficit.     

Delayed neural degeneration following gamma knife radiosurgery in a patient with an arteriovenous malformation: A diffusion tensor imaging study

Gamma knife surgery (GKS) is a proven modality for the treatment of arteriovenous malformations (AVMs), but neural degeneration is a serious complication of GKS. In this study, we report on a patient who displayed delayed neural degeneration following GKR, using diffusion tensor imaging (DTI). A 43-year-old male patient was diagnosed with an intraventricular hemorrhage (IVH) due to rupture of an AVM in the right middle cerebellar peduncle, and exhibited cognitive impairment, quadriparesis, and ataxia after IVH onset. He underwent GKS 5 weeks after onset. Brain MRIs performed at 6 weeks, 7 months, and 21 months post-onset revealed encephalomalactic lesions in the right pons, middle cerebellar peduncle, and medulla oblongata. DTI at 6 weeks post-onset suggested neural injuries of the right corticospinal tract (CST), right middle cerebellar peduncle (MCP), and right inferior cerebellar peduncle (ICP). DTI at 7 months suggested that the right CST and right ICP had recovered to some extent, which concurred with improved clinical manifestations. However, at 21 months, four neural tracts (right CST, right MCP, and both ICPs) appeared to have degenerated, which was in-line with aggravation of corresponding clinical manifestations. Experiences of this patient suggest DTI is a useful technique for the detection of neural degeneration after GKS.     

Corticospinal tract recovery in a patient with traumatic transtentorial herniation

Transtentorial herniation is one of the causes of motor weakness in traumatic brain injury. In this study, we report on a patient who underwent decompressive craniectomy due to traumatic intracerebral hemorrhage. Brain CT images taken after surgery showed intracerebral hemorrhage in the left fronto-temporal lobe and left transtentorial herniation. The patient presented with severe paralysis of the right extremities at the time of intracerebral hemorrhage onset, but the limb motor function recovered partially at 6 months after onset and to nearly normal level at 27 months. Through diffusion tensor tractography, the left corticospinal tract was disrupted below the cerebral peduncle at 1 month after onset and the disrupted left corticospinal tract was reconstructed at 27 months. These findings suggest that recovery of limb motor function in a patient with traumatic transtentorial herniation can come to be true by recovery of corticospinal tract.     

Kernohan's notch phenomenon in chronic subdural hematoma: MRI findings.

We report two cases of Kernohan's notch phenomenon secondary to chronic subdural hematoma detected by MRI. In the first case, the patient was drowsy with an oculomotor palsy and a hemiparesis ipsilateral to the chronic subdural hematoma. MRI in the post-operative period showed no abnormal signal or deformity of the crus cerebri. The neurological signs immediately resolved after trephination. In the second case, the patient was admitted with progressive decrease in their level of consciousness and ipsilateral hemiparesis with the chronic subdural hematoma. MRI on admission revealed an abnormal signal in the contralateral crus cerebri against the chronic subdural hematoma. After surgery, the mental state gradually recovered to normal with some degree of residual hemiparesis. In patients with chronic subdural hematoma, a compressive deformity of the crus cerebri, without abnormal signal on MRI, may predict a better neurological recovery in patients with Kernohan's notch phenomenon.     

脑桥梗死后皮质脊髓束的完整性：弥散张量纤维束成像验证

We report on a patient with subdural hematoma who was evaluated by diffusion tensor image(DTI) follow-up study before and after surgery. A 58-year-old male patient and ten age-matched control subjects were evaluated. The patient showed mild hemiparesis for 3 weeks prior to surgery. His hemiparesis was recovered to a nearly normal state at 5 weeks post-surgery when the follow up DTI was scanned. DTIs were acquired using a sensitivity-encoding head coil at 1.5 T. The corticospinal tract(CST) was evaluated using DTI-Studio software and the CST was ascertained by choosing the fibers passing through both the upper pons and the lower pons on the color map. Two DTI parameters(fractional anisotropy and apparent diffusion coefficient) were measured along the CST. Pre-surgery DTI showed that the CST of the affected hemisphere seemed to be injured or compressed according to the level. However, follow up DTI showed recovery of this CST to a normal state. It seems that DTI would be a useful tool for evaluation of the effect of subdural hematoma.     

Magnetic resonance imaging findings of Kernohan-Woltman notch in acute subdural hematoma.

OBJECTIVE AND IMPORTANCE: We report the case of a 73-year-old patient who presented a right motor deficit caused by an ipsilateral acute subdural hematoma. A magnetic resonance imaging (MRI) demonstration of Kernohan-Woltman notch phenomenon was obtained. CLINICAL PRESENTATION: The woman sustained a major head injury at home, followed by loss of consciousness. On admission to the emergency room, she was comatose, anisochoric (left > right), and showed a reaction to pain with decerebrating movements of left limbs (Glasgow Coma Scale (GCS) 4/15). A right severe hemiparesis was observed. Cerebral computed tomography scan showed a large right hemispheric subdural hematoma. INTERVENTION AND POST-OPERATIVE COURSE: A wide right craniotomy was performed and the subdural hematoma evacuated. During the post-operative period, the level of consciousness gradually improved. A MRI performed about 2 weeks after operation showed a small area of abnormal signal intensity in the left cerebral peduncle. On discharge, the woman was able to communicate with others, but her right hemiparesis was still severe.     

Rendu-Osler-Weber syndrome presented paramedian thalamic and midbrain infarcts and primary medullary hemorrhage: a case report

We reported a 41-year-old male with paramedian thalamic and midbrain infarcts due to cerebral embolism from bilateral pulmonary arterio-venous fistula and primary medullary hemorrhage. The patient had an episode of sudden onset consciousness disturbance with left Weber's syndrome (right hemiplegia and left oculomotor palsy) and vertical gaze palsy at age of 23. He noticed numbness in the left hand and the left half body under clavicular when he had got up in a morning at age 41. He had headache and left tinnitus on second and third days, and on the 3rd and 4th days, he experienced nausea. He had severe hiccup persisting from the 6th to the 13th days. The 23rd days he was admitted to our hospital. He showed dysesthesia and paresthesia in left half body under clavicular, dysesthesia in left hand and vertical gaze palsy and convergence disturbance. MRI performed on the 18th and 24th days, disclosed hyperdense mass in T1 and T2-weighted images in dorsal site of medulla, but the 70th days MRI showed no abnormal lesions. Therefore we diagnosed the high intensity mass as primary medullary hemorrhage. Cerebral angiography showed no abnormal vasculature. Many members of his family had history of sever nasal bleeding. He had skin hemangioma and mucosal hemangioma in esophagus, stomach, colon and rectum, and bilateral pulmonary arterio-venous fistula which had been operated at age 39. His mother also had skin hemangioma and pulmonary arterio-venous fistula. Therefore this family was diagnosed Rendu-Osler-Weber syndrome (hereditary hemorrhagic telangiectasia). MRI also disclosed multiple cerebral infarctions in bilateral thalamus, left cerebral peduncle and left cerebellar hemisphere.(ABSTRACT TRUNCATED AT 250 WORDS)     

Motor recovery via aberrant pyramidal tract in a patient with a cerebral peduncle infarct*●

The presence of the aberrant pyramidal tract has been demonstrated by several studies;however,little is known about its role in motor recovery in stroke patients.In the present study,we reported a 69-year-old right-handed female patient with an infarct in the mid to lateral portion of the left cerebral peduncle,who showed an aberrant pyramidal tract by diffusion tensor tractography.The patient presented with severe weakness of the right extremities at stroke onset.The patient showed progressive motor recovery as much as being able to extend the affected extremities against some resistance at 6 months after onset.At 20 months after stroke onset,motor function of the left extremities had recovered to a nearly normal state.Diffusion tensor tractography results showed that the PT was disrupted at the lower midbrain of the affected(left) hemisphere at 3 weeks after stroke onset and this disruption was not changed at 20 months.An aberrant pyramidal tract in the left hemisphere was also observed,which originated from the primary motor cortex and descended through the corona radiata,posterior limb of the internal capsule,thalamus,the medial lemniscus pathway from the midbrain to the pons,and then entered into the pyramidal tract area at the pontomedullary junction.Transcranial magnetic stimulation did not elicit motor evoked potential from the affected hand muscle at 3 weeks,but it elicited motor evoked potential with mildly delayed latency and low amplitude in the affected hand muscle at 20 months.The main motor functions of the affected extremities in this patient appeared to be recovered via this aberrant pyramidal tract.     

A case of duret hemorrhage demonstrated by computed tomography]

Brainstem hemorrhage in descending transtentorial herniation is well known as Duret hemorrhage. However, CT or MRI rarely reveals Duret hemorrhage. The authors report a case of brainstem hemorrhage after craniotomy of spontaneous acute subdural hematoma. A 47-year-old man suffered sudden onset of severe headache and progressive consciousness disturbance. Initial CT scan demonstrated a right acute subdural hematoma and a marked shift of the midline structures to the left. Emergency craniotomy was performed but he remained comatose. CT scan after 8 days showed multiple petechial hemorrhages in the brainstem. We reported a rare case of Duret hemorrhage diagnosed by CT scan. Duret hemorrhage is almost fatal.     

Syndrome of transtentorial herniation: is vertical displacement necessary?

MRI from a comatose patient with a massive acute subdural haematoma showed most of the features of transtentorial herniation described in the classic pathology literature. In addition to encroachment on the perimesencephalic cisterns, infarction in the anterior and posterior cerebral artery territories, ischaemic change in the lower diencephalon, and ventricular enlargement were visualised. Despite the clinical syndrome and these secondary changes due to compression, there was only approximately 2 mm of downward displacement of the upper brainstem compared with 13 mm horizontal displacement. Although tissue shifts adjacent to the tentorial aperture cause brainstem and vascular compression, these changes may occur with minimal downward herniation.     

The pathogenesis of anosognosia for hemiplegia

We compared patients with unawareness of hemiplegia lasting more than 1 month after right hemisphere stroke with other patients with right hemisphere stroke who became aware of hemiplegia within a few days after onset. Patients with persistent unawareness invariably had severe left hemisensory loss and usually had severe left spatial neglect. They were almost always apathetic; their thought lacked direction, clarity, and flexibility, and they had at least moderate impairment of intellect and memory. Their right hemisphere strokes were large and always affected the central gyri or their thalamic connections and capsular pathways. In addition, there was evidence of at least mild left hemisphere damage, most commonly caused by age-associated atrophy. The pathogenesis of anosognosia for hemiplegia may involve failure to discover paralysis because proprioceptive mechanisms that ordinarily inform an individual about the position and movement of limbs are damaged, and the patient, because of additional cognitive defects, lacks the capacity to make the necessary observations and inferences to diagnose the paralysis. We discuss the implications of this "discovery" theory and contrast it with other explanations of anosognosia.     

Diffusion tensor imaging studies on corticospinal tract injury following traumatic brain injury: a review

The corticospinal tract (CST) is the most important neural tract for motor function in the human brain. Therefore, clarification of CST injury would be an important topic in traumatic brain injury (TBI) rehabilitation. In this review, I reviewed diffusion tensor imaging (DTI) studies on CST injuries in terms of etiology and recovery in patients with TBI. Although DTI has several unique advantages for research on CST injury in TBI, only a dozen DTI studies on this topic have been reported: etiology of CST injury (9 studies), recovery of CST injury (3 studies). As for the etiology of CST injury in TBI, the previous studies have demonstrated the usefulness of DTI in diagnosis of CST injury in cases of diffuse axonal injury, transtentorial herniation, cerebral hemorrhage, and cortical contusion; moreover, according to the severity of TBI. The three studies on recovery of CST injury focused on recovery of a CST injured by diffuse axonal injury. In the future, we suggest an increase in the total number of DTI studies on this topic. In particular, research on recovery of CST injury should be encouraged. Moreover, studies of the various recovery mechanisms related to the CST are necessary.     

Diffusion tensor imaging for measuring recovery from cerebellar peduncle injury due to intracerebral hemorrhage A case report

Diffusion tensor tractography (DTT) in diffusion tensor imaging (DTI) examination allows for the three-dimensional visualization of cerebellar peduncles. The present case-control study analyzed the relationship between functional recovery of intracerebral hematoma patient and cerebellar peduncle injury, as detected by DTI. The enrolled patient could not sit at 3 weeks after onset, but was able to walk independently and perform most daily activities after 4 months. The 3-week DTT images revealed that all six cerebellar peduncles were compressed by the hematoma, posterior portions of all three left cerebellar peduncles were shortened, and the left middle cerebellar peduncle was interrupted in the mid-portion. The 4-week DTT images showed that all compressed cerebellar peduncles were ameliorated, although injured posterior portions of the three left cerebellar peduncles did not recover. The fractional anisotropy value of the right inferior cerebellar peduncle increased from two standard deviations below the normal control value to within two standard deviations of the normal control value. These findings suggested that functional recovery was primarily due to decompression of compressed cerebellar peduncles, and not to recovery of injured cerebellar peduncles. DTI evaluations of cerebellar peduncles could be helpful when cerebellar peduncle injury is suspected.     

4000/扩散张量成像对正常成人皮质脊髓束通路初步研究

目的：扩散张量成像（DTI）对健康成人皮质脊髓束通路的研究,分析不同部位皮质脊髓束通路FA值,为皮质脊髓束病理改变的研究提供正常解剖依据。材料与方法：健康成人30名, GE 1.5T及工作站行数据收集和后处理, 测量延髓、脑桥、大脑脚、基底节、放射冠及半卵园中心等层面的皮质脊髓束（CST）通路FA值。结果：延髓及半卵园中心平面的各层面FA值左右差异无显著性;脑桥、大脑脚、基底节、放射冠等水平面的各层面的FA值左右侧差异有显著性,可认为左侧较右侧高。结论：皮质脊髓束通路FA值左右侧在不同水平的层面上有差异,左侧高于右侧,可能与右利手有关。     

A study of functional plasticity of the brain in childhood. I. Critical period dislodging lateralization of language in the brain]

To investigate the functional plasticity of the brain in childhood, the intelligence and language tests, brain CT and dichotic listening test were performed on 34 patients with hemiplegia. All 13 patients with left hemiplegia, 8 to 37 years old, showed a right ear dominance suggesting the lateralization of language in the left hemisphere. Among 21 patients with right hemiplegia, 7 to 22 years old, 16 patients who had suffered from the left hemispheric damage before 6 years and 1 month of age, showed the left ear dominance suggesting the lateralization of language in right hemisphere except 2 patients. On the contrary, 3 patients with right hemiplegia who had suffered from the left hemispheric damage after 6 years and 6 months of age showed a right ear dominance. It was concluded that the critical period for the dislodging of language lateralization in the brain from the damaged left hemisphere to the intact right hemisphere is the first half of 6 years after birth. Five patients out of 8 patients with right hemiplegia showed significantly lower scores in performance than in verbal WISC IQ. The compensation of language function rather than performance function was considered to be characteristic for the left-hemispheric damage in childhood.     

Locked-in syndrome due to tentorial herniation

A 28-year-old man had a chronic locked-in syndrome following tentorial herniation caused by an epidural hematoma. Postmortem examination revealed bilateral corticospinal tract degeneration caudal to the midbrain, with infarction of the right internal capsule just rostral to the cerebral peduncle and pressure necrosis of the pyramidal portion of the left cerebral peduncle.     

Kernohan's phenomenon associated with left ruptured occipital arteriovenous malformation.

A 23-year-old woman presented with ipsilateral hemiparesia due to rupture of a left occipital arteriovenous malformation (AVM). Emergency decompression (the onset-operation interval was 46 minutes,) was carried out and the patient could leave the hospital upon recovery without neurological deficits. In general, Kernohan's phenomenon is caused by the gradual displacement of the cerebral peduncle against the tentorial edge caused by compression by the contralateral mass. This phenomenon is very rare among the cases with spontaneous intracranial hemorrhage and only three cases including the present one have been reported in the literature. In all cases the onset-operation intervals of were very short. Kernohan's phenomenon associated with a ruptured AVM is a rare condition and emergency decompression is required.     

A study on functional plasticity of the brain in childhood. II. Speech development and intelligence after the damage of cerebral hemisphere under 1 year of age]

To investigate the functional plasticity of the brain in childhood, the speech development, the intelligence test and dichotic listening test were performed on 27 patients who had suffered from hemiplegia under 1 year of age. Among 13 patients with right hemiplegia, 7 to 24 years old, 11 patients showed a left ear dominance suggesting the lateralization of language in the right hemisphere. All 14 patients with left hemiplegia, 5 to 37 years old, showed a right ear dominance suggesting the lateralization of language in the left hemisphere. All 27 patients acquired speech function enough to converse with other people during daily life. There were no differences in speech development or intelligence scores between both groups of hemiplegia. Although there was no correlation between the speech development and the age of onset of hemiplegia, there was a correlation between the speech development and the intelligence score in both groups of hemiplegia.     

Hemiconvulsion-hemiplegia syndrome and primary human herpesvirus 7 infection

We report a case of hemiconvulsion-hemiplegia (HH) syndrome. An 18-month-old female infant had a hemiconvulsion followed by left hemiplegia. Magnetic resonance imaging immediately after the onset of hemiplegia showed high intensity in the right hemisphere in diffusion-weighted images (DWI), while T1- and T2-weighted images were normal. Single photon emission computed tomography showed hypoperfusion of the right hemisphere in the acute phase. Virological analyses proved primary human herpesvirus 7 (HHV-7) infection. DWI are useful for the early evaluation of HH syndrome. Vascular disorders due to HHV-7 infection may have been related to the development of HH syndrome in this patient.