title: Neonatal-onset brainstem reticular reflex myoclonus following a prenatal brain insult: generalized myoclonic jerk and a brainstem lesion.
abstract: Brainstem reticular reflex myoclonus (BRRM) is characterized by sudden, generalized, shock-like movements that can be elicited by sensory stimulation. We present a boy, born after 35 weeks gestation, who was diagnosed with neonatal-onset BRRM. Within 1 hr of birth, the patient showed spasticity and generalized clonic movements of all limbs elicited with tactile stimulation anywhere on the body. Surface electromyography showed co-contraction of agonistic and antagonistic muscles, revealing that his generalized clonic movements were tremulous myoclonus in nature. Brain magnetic resonance imaging (MRI) at 21 hrs after birth disclosed high-intensity lesions in the Rolandic area, thalamus, basal ganglia, and brainstem, including the dorsal pons and medulla, the center of BRRM, in T1-weighted images. Follow-up MRI at 1 month revealed dramatic improvement in the pontine lesion. The patient showed gradual remission of the characteristic movements, which disappeared at 1 year of age, but the patient died unexpectedly at 1 year and 3 months. In conclusion, neonatal BRRM arises as a result of severe brainstem injury, and the associated lesions may only be seen temporarily on MRI taken soon after birth.
authors.affiliation: Department of Pediatrics, Tohoku University Graduate School of Medicine, and Tohoku Kosei Nenkin Hospital, Sendai, Japan. kakisuke@mui.biglobe.ne.jp
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kakisaka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Haginoya
authors.forename: Noriko
authors.initials: N
authors.lastname: Togashi
authors.forename: Taro
authors.initials: T
authors.lastname: Kitamiura
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Uematsu
authors.forename: Naomi
authors.initials: N
authors.lastname: Hino-Fukuyo
authors.forename: Shigeo
authors.initials: S
authors.lastname: Kure
authors.forename: Junko
authors.initials: J
authors.lastname: Saito
authors.forename: Setsuko
authors.initials: S
authors.lastname: Kitaoka
authors.forename: Shuei
authors.initials: S
authors.lastname: Watanabe
authors.forename: Hideto
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nara
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tsuchiya
mesh_terms: D004576:Electromyography; D017809:Fatal Outcome; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D009207:Myoclonus / Q000209:etiology* / Q000473:pathology*; D049188:Prenatal Injuries / Q000473:pathology*; D012021:Reflex, Abnormal; D012154:Reticular Formation / Q000293:injuries*