Determining the exact cause of CNH has proven to be difficult, specifically because only 21 additional cases have been reported since Plum and Swanson’s initial report of the condition in 1959. These subsequent reports deal only with conscious patients presenting with CNH, though the varied pathophysiologies present in each individual patient makes it nearly impossible to implicate either a particular structural lesion or the destruction of a specific locus as the sole cause of CNH. Compilations of the reports, however, have led to generalized conclusions about the primary role of structural lesions in the initiation of both juvenile and adult cases of CNH. Tumor-Induced CNH in Adults The majority of adult patients experiencing CNH have clinical histories of infiltrative, expanding tumors of the cortex, primarily involving the brainstem. Over three-quarters of the cases reported since the discovery of CNH by Plum and Swanson had tumors clearly involving the pons, with specific consideration given to pathology of the pontine tegmentum. CNH was also reported in patients with tumors affecting the medulla oblongata. Though a diagnosis of CNH is rarely considered without evidence of brainstem infiltration, there have been other reported cases of CNH not directly involving the pons or medulla. CNH was also reported in cases involving a frontal lobe tumor, an invasive laryngeal carcinoma compressing the midbrain, an extension of tumors of the head and neck into the base of the brain, and thalamic hemorrhage. The manifestation of CNH in patients with these non-brainstem related disorders leads to greater debate about the pathophysiology of CNH and the role of other parts of the brain in the regulation of respiration. At this time, there have been no reported cases of CNH associated with stroke. In each case, the nature of the tumor varied, though the two main categories of tumor were classified as either cerebral lymphomas or solid tumors, such as pontine gliomas, anaplastic medulloblastoma, or astrocytomas. Particular attention is given to the high incidence of cerebral lymphomas associated with adult CNH. Intracerebral B-cell lymphoma represents less than 1% of all primary malignant tumors of the central nervous system. Infiltration of lymphoma cells into the pons and medulla is the most frequently reported cause of CNH, accounting for half of all CNH-inducing brain tumors, despite its considerable rarity. It has been suggested that these lymphomas are capable of diffusely penetrating the midbrain, without significantly destructing the overall structures. Tumor-Induced CNH in Children CNH in children is considerably less common, and only five of the twenty one cases have been documented in children aged 11 and younger. The primary difference between juvenile and adult cases of CNH is the structural identity of the tumors leading to CNH symptoms. Four of the five cases of CNH involving children were associated with solid infiltrative gliomas on the brainstem, while only one case was associated with an apparent lymphoma referred to as microgliomatosis. Non-tumor Induced CNH There have been only a few reported cases of non-tumor induced CNH, most of which have been successfully treated. Recently, the anticonvulsant drug Topiramate induced temporary CNH in patients, which abated after drug use was terminated. Additionally, there has been one reported case of CNH in a patient suffering from multiple sclerosis with brainstem lesions. The CNH was considered reversible and was successfully treated with high-dose intravenous methylprednisolone and plasma exchange.
Central neurogenic hyperventilation
Central sleep apnea
Exercise-induced bronchoconstriction
Hypoxic ventilatory response
Hypoxic pulmonary vasoconstriction
Central hypoventilation syndrome
Intermittent hypoxia
Histotoxic hypoxia