Spinal Epidural Hematoma Due to Venous Congestion Caused by Nutcracker Syndrome.

The causes of spinal epidural hematoma (SEH) have been attributed to coagulopathy, trauma, vascular anomalies, and so forth. The incidence of vascular anomalies shown by digital subtraction angiography has been reported to be 15%, and most cases have been reported to be spinal epidural arteriovenous fistulae. SEH has rarely been caused by venous congestion. We report a case of SEH in a 78-year-old male who presented to our emergency department with sudden-onset back pain, followed by complete paraplegia with bladder and rectal disturbance. Magnetic resonance imaging revealed a dorsally placed extradural hematoma extending from T10 to L1. An urgent laminectomy from T11 to L2 was performed. Computed tomography angiography (CTA) performed 1 week after the operation showed compression of the left renal vein between the aorta and superior mesenteric artery with dilation of the surrounding veins, including the spinal epidural venous plexus, at the same level as the hematoma. This was diagnosed as Nutcracker syndrome (NCS), which was consistent as a cause of SEH. The patient's symptoms gradually improved, and after 6 months, he regained normal strength in his lower extremities, but bladder and rectal disturbance remained and required intermittent self-catheterization. We chose conservative treatment for NCS, and SEH did not recur until the patient died of a cause unrelated to SEH or NCS. SEH could occur secondary to venous congestion including NCS. We emphasize the importance of investigating venous return to evaluate the etiology of SEH, which can be clearly visualized using CTA.

100 Hz operation in 10 PW/sr·cm2 class Nd:YAG Micro-MOPA.

An Nd:YAG Micro-MOPA, based on a microchip master oscillator and power amplifier system with gain aperture beam cleaning, could generate sub-ns 200 mJ pulses with extremely high brightness of 18 PW/sr·cm2 [Opt. Express268609 (2018)]. However, the system repetition rate was limited to 10 Hz, due to thermal problems occurring in the main amplifier rod under high-power operation. In this work, we achieved 100 Hz operation with pulse brightness of 11 PW/sr·cm2 by optical compensation of thermal lensing, which was evaluated through calculations and an experiment.

Superior Oblique Myokymia: A Case Report of Surgical Treatment, Review of the Literature, and Consideration of Surgical Approach.

BACKGROUND: Superior oblique myokymia (SOM) is a rare disorder characterized by episodic microtremor of the eyeball. in patients with SOM, intermittent contraction of the superior oblique muscle causes irregular and rotatory eye movement, causing oscillopsia and diplopia. Microvascular decompression (MVD) of the trochlear nerve is potentially a definitive treatment method for SOM; however, owing to its rarity, this disorder is not well-known to neurosurgeons, and thus the optimal surgical approach has not yet been determined. CASE DESCRIPTION: A 77-year-old woman with left SOM had experienced oscillopsia for 2 years. MVD was performed via a left lateral superior cerebellar approach with the patient in the park-bench position. Her symptom resolved immediately after the surgery. CONCLUSIONS: We believe that MVD via a left lateral superior cerebellar approach can be safely performed to SOM in elderly patients like our patient. Therefore, MVD should be considered as the definitive treatment method for more patients with SOM.

Clival Metastasis of Hepatocellular Carcinoma with an Initial Histopathological Diagnosis of Atypical Pituitary Adenoma.

Histologically, hepatocellular carcinoma (HCC) and atypical pituitary adenoma are similar, posing a potential clinical problem. A 76-year-old woman, whose past medical history was significant for hepatitis C virus (HCV), positivity without liver cirrhosis was presented with abducens nerve (CN VI) palsy. Contrast-enhanced magnetic resonance imaging (MRI) showed a clival tumor with infiltration of the right cavernous sinus. Subtotal resection was performed using a right anterior petrosal approach. Histological diagnosis was pituitary adenoma. Thirty-four days after the operation, MRI imaging showed residual tumor growth without any liver masses on computed tomography (CT). The patient underwent a second operation using an endoscopic transnasal transsphenoidal approach. Histological examination of the specimen gave a positive reaction for α -fetoprotein. Repeat whole-body CT showed an enhanced liver mass. Based on these findings, the lesion was diagnosed as metastatic HCC. The patient died of liver failure 6 months later. In this case, tumor diagnosis was difficult because of the histological similarity of HCC and pituitary adenoma, and the fact that the clival tumor grew prior to presentation of the liver mass on CT. This case emphasizes the importance of comparing the pathological diagnosis with the patient's clinical course.

Sciatic Neuralgia Caused by May-Thurner Syndrome.

BACKGROUND: Sciatic neuralgia (SN) is a type of pain commonly associated with lumbosacral radiculopathy. May-Thurner syndrome (MTS) is a disease characterized by venous congestion in the left common iliac vein (LCIV) due to right common iliac artery compression. A case of MTS with SN as the first presenting symptom is described. CASE DESCRIPTION: A 53-year-old man gradually developed left SN; however, radiologic examination showed no causal findings. Conservative medical treatment did not result in satisfactory pain relief. During the follow-up period, edema and brownish skin pigmentation were noted on the left crural region. Follow-up magnetic resonance imaging of lumbar spine revealed vascular enlargement around the spine and compression of the LCIV by the right common iliac artery. Furthermore, the left S1 nerve root was compressed by enlarged veins, which was thought to be the cause of the left S1 radiculopathy and SN. After the stenosed part of the LCIV was expanded, the pain and edema in the left leg disappeared. CONCLUSIONS: This is the first report of SN associated with MTS. MTS should be considered as one of the differential diagnoses of SN. Thus, symptoms such as pain, edema, and skin hyperpigmentation on the left leg should be closely noted.

Serotonin mediates cross-modal reorganization of cortical circuits.

Loss of one type of sensory input can cause improved functionality of other sensory systems. Whereas this form of plasticity, cross-modal plasticity, is well established, the molecular and cellular mechanisms underlying it are still unclear. Here, we show that visual deprivation (VD) increases extracellular serotonin in the juvenile rat barrel cortex. This increase in serotonin levels facilitates synaptic strengthening at layer 4 to layer 2/3 synapses within the barrel cortex. Upon VD, whisker experience leads to trafficking of the AMPA-type glutamate receptors (AMPARs) into these synapses through the activation of ERK and increased phosphorylation of AMPAR subunit GluR1 at the juvenile age when natural whisker experience no longer induces synaptic GluR1 delivery. VD thereby leads to sharpening of the functional whisker-barrel map at layer 2/3. Thus, sensory deprivation of one modality leads to serotonin release in remaining modalities, facilitates GluR1-dependent synaptic strengthening, and refines cortical organization.