Robot-assisted stereotactic brainstem biopsy in children: prospective cohort study.

Tumours located within the brainstem comprise approximately a tenth of all paediatric brain tumours. Surgical biopsy of these tumours is technically challenging and has historically been associated with considerable risk. To this end, robot-assisted surgery theoretically allows for increased accuracy and precision. In this study we report our experience using the Neuromate robot (Renishaw, Gloucestershire, UK) to perform robot-assisted stereotactic biopsy in children with tumours located within the brainstem. An uncontrolled prospective cohort study was performed (phase II) according to the IDEAL model for safe surgical innovation. All cases were recorded on a prospectively maintained database. The database was searched over a 2-year period between the 1st December 2015 and the 31st November 2017 to identify all children with brainstem tumours that underwent robot-assisted stereotactic brain biopsy. When accessible, the post-operative MRI scans and pre-operative plans were compared to assess the target point localisation error (TPLE). Adverse events were recorded prospectively according to whether they resulted in increased hospital stay, caused neurological injury, or lead to death. In all, 11 consecutive children were identified with brain tumours located within the brainstem. In 10/11 cases specimens were diagnostic; in the remaining case a further biopsy was successful. The most frequent pathology was DIPG (7/15). Seven patients underwent an early post-operative volumetric MRI; the calculated median TPLE was 2.7 mm (range 0.5-4.2 mm). There were no surgical complications noted. Robot-assisted stereotactic biopsy in children appears to be feasible and safe. Research databases and comparative studies are warranted to further assess the technique.

A life-threatening brainstem compression by cerebral Echinococcus granulosus.

Cystic echinococcosis (CE) is a zoonotic disease caused by Echinococcus granulosus. It is of worldwide importance, and is widespread in the Mediterranean region and Middle East. This tapeworm shows great intraspecific variation in relation to host specificity, epidemiology and morphology. This variability led in previous years to the identification of ten (G1-G10) different genotypes of the parasite. Cerebral localization of E. granulosus is not common: it especially affects children and is more frequently located in the supratentorial region. It can be life-threatening due to its localization in eloquent areas especially in the posterior fossa. Despite the benign nature of hydatid cyst, invasion of critical areas may cause significant mortality and morbidity in some patients. Urgent surgical decompression and adjuvant medical treatment must be employed as soon as possible in these patients. We present a clinical case of life-threatening brainstem compression in a child due to a rare form of CE which was confirmed with biomolecular techniques. She presented with respiratory distress and progressive quadriparesis. All cysts were removed by microsurgical technique and albendazole was given postoperatively for one year with regular follow-ups.

Fatal infection in two Icelandic stallions caused by Halicephalobus gingivalis (Nematoda: Rhabditida).

Opportunistic infections with the free living nematode Halicephalobus gingivalis are infrequently reported in horses but the cases are widespread geographically. The nematodes are believed to penetrate wounds and subsequently reproduce within the host tissues. This paper reports two cases of a fatal disease in stallions of the Icelandic breed in Iceland. Case 1: a stallion, which sustained injuries to the mouth after an accident, developed severe neurological signs and had to be euthanatized. Histological examination revealed mild inflammation and malacia in the cerebellum associated with the presence of numerous H. gingivalis nematodes. Case 2: a stallion that started swerving to one side and lost balance was euthanatized due to lack of response to therapy and rapid deterioration. Histological examination revealed numerous H. gingivalis nematodes in the cerebellum, brain stem, cervical spinal cord and in the meninges, with minimal reactive changes. In case 1 the infection presumably was acquired by nematodes from soil penetrating through wounds in the mouth. The mode of the H. gingivalis infection in case 2 is uncertain. These are the first cases of H. gingivalis infection reported from Iceland and the second report from the Nordic countries.

Toxoplasma granuloma of brainstem: a rare case.

Toxoplasmosis is a common opportunistic infection in patients with AIDS in whom it frequently presents as intracranial space-occupying lesions. In the immunocompetent patient the most common manifestation is as asymptomatic cervical lymphadenopathy which may be associated with vague systemic manifestations such as fever or myalgia. In very rare cases people with normal immunity may present with meningoencephalitis polymyositis or myocarditis. It is very rare to encounter a brainstem granuloma due to toxoplasma infection in such patients. We report a non-immunocompromised man who presented with multiple cranial nerve palsies due to a brainstem lesion, which turned out to be a toxoplasma granuloma. He recovered completely after a four-week course of Pyrimethamine and Sulphadoxine. An extensive search of the literature failed to reveal any prior reports of a similar nature. This case is being reported because of its rarity and the complete recovery made by the patient.

Fatal subacute necrotising brainstem encephalitis in a young man due to a rare parasitic (Balamuthia) infection.

We describe a case of brainstem inflammation in a young man which at first defied diagnosis. However, after his death, and notwithstanding our inability to find a cause at autopsy, we did not give up. After sending paraffin blocks to the Centers for Disease Control in Atlanta, Georgia, USA, they suggested the diagnosis of Balamuthia (amoebic) infection.

Muscarinic receptors and alpha2-adrenoceptors interact to modulate the respiratory rhythm in mouse neonates.

The respiratory rhythm generator (RRG) is modulated by several endogenous substances, including acetylcholine (ACh) and noradrenaline (NA) that interact in several modulatory processes. To know whether ACh and NA interacted to modulate the RRG activity, we used medullary "en bloc" and slice preparations from neonatal mice where the RRG has been shown to receive a facilitatory modulation from A1/C1 neurons, via a continuous release of endogenous NA and activation of alpha2 adrenoceptors. Applying ACh at 25 microM activated the RRG but ACh had no effects at 50 microM. Applying the ACh receptor agonists nicotine and muscarine facilitated and depressed the RRG, respectively. After yohimbine pre-treatment that blocked the alpha2 facilitation, the nicotinic facilitation was not altered, the muscarinic depression was reversed and ACh 50 microM significantly facilitated the RRG. After L-tyrosine pre-treatment that potentiated the alpha2 facilitation, the muscarinic depression was enhanced. Thus, ACh regulates the RRG activity via nicotinic and muscarinic receptors, the muscarinic receptors interacting with alpha2 adrenoceptors.