WNT1-associated osteogenesis imperfecta with atrophic frontal lobes and arachnoid cysts.

A rare form of osteogenesis imperfecta (OI) caused by Wingless-type MMTV integration site family 1 (WNT1) mutations combines central nervous system (CNS) anomalies with the characteristic increased susceptibility to fractures. We report an additional case where arachnoid cysts extend the phenotype, and that also confirms the association of intellectual disabilities with asymmetric cerebellar hypoplasia here. Interestingly, if the cerebellum is normal in this disorder, intelligence is as well, analogous to an association with similar delays in a subset of patients with sporadic unilateral cerebellar hypoplasia. Those cases typically appear to represent vascular disruptions, and we suggest that most brain anomalies in WNT1-associated OI have vascular origins related to a role for WNT1 in CNS angiogenesis. This unusual combination of benign cerebellar findings with effects on higher functions in these two situations raises the possibility that WNT1 is involved in the pathogenesis of the associated sporadic cases as well. Finally, our patient reacted poorly to pamidronate, which appears ineffective with this form of OI, so that a lack of improvement is an indication for molecular testing that includes WNT1.

Magnetic resonance imaging provides evidence of glymphatic drainage from human brain to cervical lymph nodes.

Pre-clinical research in rodents provides evidence that the central nervous system (CNS) has functional lymphatic vessels. In-vivo observations in humans, however, are not demonstrated. We here show data on CNS lymphatic drainage to cervical lymph nodes in-vivo by magnetic resonance imaging (MRI) enhanced with an intrathecal contrast agent as a cerebrospinal fluid (CSF) tracer. Standardized MRI of the intracranial compartment and the neck were acquired before and up to 24-48 hours following intrathecal contrast agent administration in 19 individuals. Contrast enhancement was radiologically confirmed by signal changes in CSF nearby inferior frontal gyrus, brain parenchyma of inferior frontal gyrus, parahippocampal gyrus, thalamus and pons, and parenchyma of cervical lymph node, and with sagittal sinus and neck muscle serving as reference tissue for cranial and neck MRI acquisitions, respectively. Time series of changes in signal intensity shows that contrast enhancement within CSF precedes glymphatic enhancement and peaks at 4-6 hours following intrathecal injection. Cervical lymph node enhancement coincides in time with peak glymphatic enhancement, with peak after 24 hours. Our findings provide in-vivo evidence of CSF tracer drainage to cervical lymph nodes in humans. The time course of lymph node enhancement coincided with brain glymphatic enhancement rather than with CSF enhancement.

Intracranial hypotension syndrome following chiropractic manipulation of the cervical spine.

Cervical spine manipulation has been associated with several disorders such as cervical arteries dissection, but rarely has a relationship with intracranial hypotension been reported. We describe a patient showing intracranial hypotension syndrome following chiropractic cervical spine treatment. Magnetic resonance showed the presence of dural leakage at cervical level, suggesting the pathogenesis of the syndrome. We state that cervical spine manipulation should be considered a treatment with risk of neurological complications, including the occurrence of intracranial hypotension.

Disappearance of central pain following iatrogenic stroke.

An exceptional case of long-standing central pain temporarily relieved by a focal stroke in the primary somatosensory area is reported. This case highlights the focal nature of central pain mechanisms and the possible value of selective subparietal leukotomies in the management of central pain.

Lateralization of cognitive processes in the brain.

The lateralization of cognitive processes in the brain is discussed. The traditional view of a language-visuo/spatial dichotomy of function between the hemispheres has been replaced by more subtle distinctions. The use of magnetic resonance imaging (MRI) to study brain morphology has resulted in a renewed focus on the relationship between structural and functional asymmetry. Focus has been on the role played by the planum temporale area in the posterior part of the superior temporal gyrus for language asymmetry, and the possible significance of the larger left planum. The dichotic listening technique is used to illustrate the difference between bottom-up, or stimulus-driven laterality versus top-down, or instruction-driven laterality. It is suggested that the hemispheric dominance observed at any time is the sum result of the dynamic interaction between bottom-up and top-down processing tendencies. Stimulus-driven laterality dominance is always monitored and modulated through top-down cognitive processes, like shifting of attention and changes in arousal. A model of top-down modulation of bottom-up laterality is presented with special reference to the understanding of psychiatric disorders.

Cerebral blood flow in normal brain tissue of patients with intracranial tumors.

Pre- and postoperative cerebral blood flow (CBF) changes in the normal brain tissue of 17 patients with intracranial tumors were studied to determine the value for planning therapeutic strategy. The tumors included eight astrocytomas, seven meningiomas, one metastasis, and one arachnoid cyst. The patients were divided into two groups based on the mass effect seen on computed tomography (CT) scans. Group A comprised six patients with midline shift or evidence of herniation; Group B, 11 patients with no mass effect or local compression only. CBF and vasoresponse to acetazolamide were measured in the bilateral hemispheres, cortices, and thalami using xenon-enhanced CT, excluding the area of tumor extension, before and 2-3 weeks after tumor excision. Preoperative CBF was reduced bilaterally but more markedly ipsilateral to the tumor. The CBF reduction was significantly greater in Group A than in Group B. Acetazolamide caused CBF to increase by 70.5-99.1% in Group B but only increase by 1.7-9.6% or paradoxically decrease in Group A. Postoperatively, the CBF tended to recover partially in Group A but persisted or deteriorated in Group B. The more pronounced CBF reduction and poor or paradoxical response to acetazolamide preoperatively and postoperative CBF restoration in Group A may indicate that ischemia was more important than metabolic depression in these patients. In contrast, the excessive response to acetazolamide and the postoperative CBF deterioration in Group B may indicate that CBF reduction was secondary to metabolic depression. Mass effect is a key predictor for functional recovery following surgical decompression of intracranial tumors.