Inability to sneeze as a manifestation of medullary neoplasm

Intractable Sneezing Unfolding a Hideous Truth

Intractable sneezing is a diagnosis of exclusion and is mostly psychogenic. We reported a case of an 11-year-old girl who presented with uncontrollable bouts of sneezing for three weeks, which did not respond to conventional treatment. She was eventually diagnosed to have psychogenic intractable sneezing, which was triggered by an unfortunate family circumstance. She improved with psychotherapy and was discharged well. Literature review on intractable sneezing showed that patients were predominately female teenagers and mostly recovered after psychotherapy. Multidisciplinary team effort especially with a child psychiatrist is important for the treatment and follow-up of these patients. Imaging should also be routinely performed as some had underlying organic causes that presented as intractable sneezing.

Paroxysmal sneezing at the onset of syncopes and transient ischemic attack revealing a papillary cardiac fibroelastoma

Sneezing can at times be associated with neurological disorders. The “sneeze center” is localized in the lateral medulla. We report the case of a 50-year-old man who presented three episodes of sneezing, two of them followed by an episode of transient gait instability and dizziness and the third one followed by an episode of transient left hemiparesis due to fibroelastoma of the aortic cardiac valve. To the best of our knowledge, this is the first description of a transient ischemic attack due to cardiac papillary fibroelastoma and revealed by violent episodes of sneezing.

Restoration of the efferent phase of the sneeze reflex after regression of an Arnold-Chiari malformation with compression of the medulla oblongata

The precise location of the sneeze center in the human brain has not been definitively identified. The aim of this report is to contribute to the effort to detect its location. We report the case of a 13-year-old boy who presented to our outpatient clinic for evaluation of an inability to sneeze. In an attempt to trigger the afferent (nasal) phase of the sneeze reflex, we first applied a cotton swab and later a silver nitrate stick to the patient's nasal mucosa. Once that was accomplished, we observed that the patient could not complete the efferent (expiratory) phase of the sneeze reflex, and thus he did not sneeze. Cranial magnetic resonance imaging (MRI) revealed that his cerebellar tonsils extended approximately 10 mm inferiorly through the foramen magnum, which represented a type I Arnold-Chiari malformation. The tonsils were noted to have compressed the posterolateral portion of the medulla oblongata. At follow-up 21 months later, we noted that the patient was able to sneeze spontaneously as well as with nasal stimulation. Repeat MRI revealed that the Arnold-Chiari malformation had undergone a spontaneous partial regression, which resulted in relief of the compression of the medulla oblongata. We believe that the patient's earlier inability to sneeze might have been attributable to the compression of the medulla oblongata by the cerebellar tonsils and that the site of the compression might represent the location of his sneeze center.

Paroxysmal sneezing after hypothalamic deep brain stimulation for cluster headache

BACKGROUND

Cluster headache (CH) is the most common of the trigeminal autonomic cephalalgias (TAC), presenting with excruciatingly severe, short-lasting, unilateral headache accompanied by cranial autonomic symptoms. Chronic CH occurs in 10-15% of patients. Deep brain stimulation in the posterior hypothalamic region (hDBS) is successful in treating about 60% of patients otherwise refractory to medical treatment.

CASE

A 28-year-old man had hDBS for medically refractory left-sided chronic CH, with a resultant reduction in frequency and severity of his attacks. He developed recurrent paroxysms of sneezing soon after the stimulation was started that have reduced after increasing the pulse width from 60 to 90 µs.

DISCUSSION

Stimulation of the brain in the region of the posterior hypothalamus could produce sneezing from activation of facial nerve parasympathetic or trigeminal afferent pathway activation through the trigeminohypothalamic tract, or through other central mechanisms. DBS in general offers the opportunity to illuminate our understanding of brain function and for CH offers particular opportunities to understand a devastating primary headache syndrome.

The role of particle size in aerosolised pathogen transmission: a review

Understanding respiratory pathogen transmission is essential for public health measures aimed at reducing pathogen spread. Particle generation and size are key determinant for pathogen carriage, aerosolisation, and transmission. Production of infectious respiratory particles is dependent on the type and frequency of respiratory activity, type and site of infection and pathogen load. Further, relative humidity, particle aggregation and mucus properties influence expelled particle size and subsequent transmission. Review of 26 studies reporting particle sizes generated from breathing, coughing, sneezing and talking showed healthy individuals generate particles between 0.01 and 500 μm, and individuals with infections produce particles between 0.05 and 500 μm. This indicates that expelled particles carrying pathogens do not exclusively disperse by airborne or droplet transmission but avail of both methods simultaneously and current dichotomous infection control precautions should be updated to include measures to contain both modes of aerosolised transmission.

Sneeze reflex: facts and fiction

Sneezing is a protective reflex, and is sometimes a sign of various medical conditions. Sneezing has been a remarkable sign throughout the history. In Asia and Europe, superstitions regarding sneezing extend through a wide range of races and countries, and it has an ominous significance. Although sneezing is a protective reflex response, little else is known about it. A sneeze (or sternutation) is expulsion of air from the lungs through the nose and mouth, most commonly caused by the irritation of the nasal mucosa. Sneezing can further be triggered through sudden exposure to bright light, a particularly full stomach and physical stimulants of the trigeminal nerve, as a result of central nervous system pathologies such as epilepsy, posterior inferior cerebellar artery syndrome or as a symptom of psychogenic pathologies. In this first comprehensive review of the sneeze reflex in the English literature, we aim to review the pathophysiology, etiology, diagnosis, treatment and complications of sneezing.

Sneezing induced by sexual ideation or orgasm: an under-reported phenomenon

We describe a hitherto under-recognized curious response in some individuals: of sneezing in response either to sexual ideation or in response to orgasm. Our review suggests that it may be much more common than expected. We surmise that an indiscrete stimulation of the parasympathetic nervous system may be an underlying mechanism to explain this and other reported unusual triggers of sneezing.

Sneeze related area in the medulla: localisation of the human sneezing centre?

Sneezing is a rarely explored symptom in neurological practice. In the cat, a sneeze evoking centre is located in the medulla. The existence of a sneezing centre has not been confirmed in humans. A case with abnormal sneezing secondary to a strategic infarct in the right latero-medullary region is presented. A 66 year old man suddenly presented paroxysmal sneezing followed by ataxia, right sided motor and sensory symptoms, and hoarseness. The application of stimuli to the right nasal fossa did not evoke sneezing nor the wish to sneeze. The same stimuli to the contralateral nasal fossa evoked normal sneezing. The preservation of the superficial sensitivity of the nasal fossa indicates that the lesion was localised in the hypothetical human sneezing centre, very close to the spinal trigeminal tract and nucleus. This centre appears to be bilateral and functionally independent on both sides.

Gliomas del tronco encefálico

Brainstem gliomas have been increasingly understood in the last two decades and they are nowadays regarded as an heterogeneous group of tumors with tendency towards the pediatric age, where they account for 10-20% of brain neoplasms. Besides the well known diffuse tumor, several subtypes, with a different biological behaviour, amenable to surgical resection and better prognosis, have been identified, giving rise to many classifications and terms. In the other way, attention has been recently paid to adult brainstem gliomas in contrast to pediatric tumors. Based on a review of the literature, we describe the different subtypes of brainstem gliomas, with particular interest on therapeutic approaches and differences between pediatric and adult tumors, employing iconography from our series.

Variant effect of first- and second-generation antihistamines as clues to their mechanism of action on the sneeze reflex in the common cold

Treatment with first-generation antihistamines reduces sneezing, rhinorrhea, nasal mucus weight, and, in some instances, cough in subjects with experimental or natural colds; however, treatment with second-generation antihistamines has not been effective for these complaints in trials in subjects with natural colds. This article reports the negative results of a clinical trial with loratadine, a second-generation antihistamine, in adults in the rhinovirus challenge model. This finding in the highly controlled setting of the challenge model confirms the earlier negative studies with second-generation antihistamines in natural colds. First-generation antihistamines block both histaminic and muscarinic receptors as well as passing the blood-brain barrier. Second-generation antihistamines mainly block histaminic receptors and do not pass the blood-brain barrier. The effectiveness of first-generation antihistamines in blocking sneezing in colds may be due primarily to neuropharmacological manipulation of histaminic and muscarinic receptors in the medulla.