Biomedical subjects

Rachel Laff

Publications and source records attributed to Rachel Laff.

3 recordsLinked to original sources

PubMed2003

Epileptic kinetopsia: ictal illusory motion perception.

A 38-year-old woman with a right posterior temporo-occipital brain tumor developed partial seizures with illusory motion perception of environmental objects going from the center to the periphery within her left visual field. Subdural EEG recordings during visual seizures revealed onsets in the right temporo-parieto-occipital junction. Her ictal visual distortion was probably caused by activation of V5, an area involved in motion perception. Given that the tumor location corresponds with the ictal onset in the V5 area, and the semiology of her seizures, this case supports that epileptic dysfunction in V5 can cause illusions of visual motion.

Adult↗

PubMed2003

Transient postoperative prosopagnosia.

A 23-year-old right-handed woman developed isolated transient prosopagnosia following surgical resection of a right posterior temporal seizure focus. At 18 years of age she had developed secondarily generalized tonic-clonic seizures. Preoperative neuropsychological evaluation was normal, and neurological examination revealed only a left superior quadrant achromatopsia. MRI revealed a circumscribed lesion in the right inferolateral temporo-occipital junction. Following surgery she was agitated for 36 hours, and afterward, when her attention and orientation improved, she was unable to recognize familiar faces. She could, however, recognize familiar voices. Her prosopagnosia resolved over the next 6-7 days. This case demonstrates that isolated prosopagnosia can occur in patients with lesions restricted to the right inferior posterior temporal-anterior occipital region. The temporary nature of the prosopagnosia may result from postsurgical tissue injury, including focal cerebral edema, with compensation by ipsilateral or contralateral areas.

Adult↗

PubMed2003

Callosal lesions and behavior: history and modern concepts.

Callosotomy has played a unique role in the treatment of epilepsy and in the understanding of human brain function. The pioneering work of Dejerine and Liepmann presenting the first findings of callosal lesion pathology at the turn of the 20th century was accepted but then quickly forgotten. Two schools resurrected the phoenix of callosal syndromes: Roger Sperry and Michael Gazzaniga leading in experimental neuroscience, and Norman Geschwind leading in clinical neurology. Callosotomy remains an effective technique to treat atonic, tonic, and tonic-clonic seizures, especially in patients with symptomatic generalized epilepsies such as Lennox-Gastaut syndrome. Neurologic, cognitive, and behavioral complications limit its use given that precise characterization of these complications as well as their frequency is difficult. The high frequencies of developmental delays, severe seizures, head injuries, antiepileptic drug burden, and other factors limit the ability to attribute a specific change to surgical intervention, since surgery can change multiple factors. For example, subtle behavioral changes in executive function and personality are difficult to delineate in a population with preexisting neurologic and psychiatric disorders. Despite this, a clearer picture of the effects of callosotomy, as defined by clinical neurology and neuropsychology as well as cognitive neuroscience, is emerging.

Animals↗