Arcsine Laws of Light.

We demonstrate that the time-integrated light intensity transmitted by a coherently driven resonator obeys Lévy's arcsine laws-a cornerstone of extreme value statistics. We show that convergence to the arcsine distribution is algebraic, universal, and independent of nonequilibrium behavior due to nonconservative forces or nonadiabatic driving. We furthermore verify, numerically, that the arcsine laws hold in the presence of frequency noise and in Kerr-nonlinear resonators supporting non-Gaussian states. The arcsine laws imply a weak ergodicity breaking which can be leveraged to enhance the precision of resonant optical sensors with zero energy cost, as shown in our companion manuscript [V. G. Ramesh et al., companion paper, Phys. Rev. Res. (2024).PPRHAI2643-1564]. Finally, we discuss perspectives for probing the possible breakdown of the arcsine laws in systems with memory.

Percutaneous retrogasserian glycerol rhizotomy for trigeminal neuralgia: A simple, safe, cost-effective procedure.

OBJECTIVE: Trigeminal neuralgia (TN) is a condition that has been studied over decades and whose pathogenesis has still not been well defined. Various open and minimally invasive procedures are in vogue for the treatment of intractable TN. All these procedures have their complications and recurrence rates. Percutaneous retrogasserian glycerol rhizotomy (PRGR) is one of the minimally invasive procedures that have been popular for quite a long time. MATERIAL AND METHODS: This paper is a prospective study analyzing the results of 93 patients with refractory TN who were treated with PRGR. RESULTS: There was an immediate pain relief in 96.8% of patients and long-term pain relief in 89.4% of patients, with a mean follow-up duration of 18.8 months. Recurrence of pain was seen in 10.4% of patients. CONCLUSIONS: The PRGR is a simple, safe, cost-effective procedure without any need for expensive equipment and with a good outcome that is compared to the other relatively more expensive open and minimally invasive procedures.

Cervical extradural and extraspinal ependymoma mimicking dumb-bell schwannoma: an unusual tumor.

Ependymomas are common in intramedullary location and extradural location of the spinal cord is very rare. A few cases in the lumbosacral region have been reported. This report presents a cervical dumb-bell ependymoma with a small intraspinal extradural component and a large extraspinal component in the posterior triangle of the neck. The tumor was excised in two stages. This is probably the first such case report in the cervical region in the world literature. Possible histogenesis of ependymoma in this location is also discussed.

Giant parenchymal cysticercosis with unusual imaging features.

Giant neurocysticercosis is a relatively rare condition. A 40-year-old woman presented with left focal seizures and progressive left hemiparesis. A CT scan of the brain showed multiple hypodense lesions in the right cerebral hemisphere with no contrast enhancement or perilesional edema. MRI showed multiple hypointense lesions in the right perisylvian area. At surgery, the lesion was found to be a single large parasitic cyst measuring approximately 5.0 x 4.5 x 5.0 cm and the same was excised. Histopathology showed a solitary cysticercus cyst with scolex. The patient made an uneventful recovery. This imaging appearance of giant neurocysticercosis is very unusual and only two similar instances have been reported thus far.

A new scale for prognostication in head injury.

The ability to predict the outcome of head injury helps in the efficient use of resources and communicating with the families of the victims. There is need for a simple, easily applicable, objective scale for accurately predicting outcome after severe head injury. A simple, objective bedside scoring system, known as the Madras Head Injury Prognostic Scale (MHIPS), has been devised. It is based upon six well-established prognostic factors: age, best motor response, pupillary light reaction, oculocephalic response, CT scan findings and other systemic injuries. Each factor has been divided into three subgroups and a score assigned based on prognosis. The maximum total score is 18 and the minimum total score is 6. The validity of this scale has been assessed both retrospectively and prospectively. The initial retrospective study involved 355 patients with severe head injury. After correlating the initial MHIPS score with outcome on discharge from the hospital, it was found that most patients with a score of 12 or under died; most patients with a score of 15 and above had a good outcome; and patients with a score of 13 and 14 were either severely disabled or vegetative. The results of the prospective study, which involved 104 patients with severe head injury, showed that the outcome of 87.5% of the patients could be predicted accurately. The MHIPS is a simple, objective, easily applicable, bedside scoring system that can be used without complex mathematical calculations and investigations.

Vertex extradural hematoma in association with Paget's disease of the skull.

Paget's disease of skull usually causes neurological complications such as basilar invagination, cranial neuropathies, etc. Occurrence of extradural hematoma in association with Paget's disease of skull is rare. A 48 year old man presented with headache and right upper limb weakness, two days after a fall from scooter. CT Scan of brain showed a large extradural hematoma at the vertex with the cranial vault showing features of Paget's disease. At surgery, no skull fracture or injury to the superior sagittal sinus was evident. There was diffuse oozing from the inner table of the skull, which showed features of Paget's disease. The extradural hematoma was evacuated and the patient made good recovery. He deteriorated a few hours after surgery. Follow up CT Scan showed diffuse brain swelling with minimal recollection of hematoma. Re-exploration showed a small recollection which was evacuated and the part of the oozing diseased skull was excised. The patient recovered completely. This is the first reported case of vertex extradural hematoma in association with the Paget's disease of skull. The unusual features are the absence of skull fracture and injury to the superior sagittal sinus. The increased vascularity of the skull due to Paget's disease has caused the hematoma by diffuse oozing from the inner table.

A case of coup and contrecoup extradural hematoma.

We report an unusual type of a bilateral extradural hematoma: one due to direct injury and another due to the contrecoup effect. The second evolved after the first hematoma was evacuated.

Extradural hematoma at the vertex: a case report.

A case of extradural hematoma of the vertex presenting 4 days after injury, which was diagnosed using magnetic resonance imaging, is reported. The relevant literature is also reviewed.

Desmoplastic infantile ganglioglioma -- a case report.

Desmoplastic infantile ganglioglioma is a very rare supratentorial tumor occurring in the first two years of life. A five-month-old female infant presented with recurrent seizures, large head and loss of acquired milestones. Computerized Tomographic Scan of brain showed a large subarachnoid cyst with a solid intensely contrast enhancing tumor in the right temporoparietal region with severe degree of mass effect. Craniotomy and total excision of the tumor followed subsequently by subduro-peritoneal shunt for the extracerebral fluid collection was done. The child made good recovery. Histopathology revealed features of desmoplastic infantile ganglioglioma, viz., marked desmoplastic component with glial and neuronal elements. Immunohistochemistry showed positive staining for glial fibrillary acidic protein (GFAP) with areas of synaptophysin and chromogranin positivity. Desmoplastic infantile ganglioglioma is a rare tumor of infancy, which has excellent prognosis after total excision. No adjuvant therapy is required. This is the first Indian report of desmoplastic infantile ganglioglioma out of less than fifty cases reported worldwide.