Thalamic contributions to anterograde, retrograde, and implicit memory: a case study.

Learning and memory deficits are typically associated with damage or dysfunction of medial temporal lobe structures; however, diencephalic lesions are another common cause of severe and persistent memory deficits. We focus specifically on the thalamus and review the pathological and neuropsychological characteristics of two common causes of such damage: Korsakoff's syndrome and stroke. We then present a patient who had sustained bilateral medial thalamic infarctions that affected the medial dorsal nucleus and internal medullary lamina. This patient demonstrated the characteristic temporally graded retrograde amnesia and a profound anterograde memory (i.e., explicit memory) deficit within the context of relatively preserved implicit memory. Implications of this explicit-implicit discrepancy are discussed within the context of cognitive rehabilitation techniques that hold promise for more severely impaired patients.

Efficacy of ketamine in anesthetic dosage for the treatment of refractory complex regional pain syndrome: an open-label phase II study.

OBJECTIVE: Advanced complex regional pain syndrome (CRPS) remains very difficult to treat. While subanesthetic low-dose ketamine has shown promise in early localized CRPS, its use in advanced CRPS has not been as effective. Since ketamine's analgesic potency and duration of effect in neuropathic pain are directly dose-dependant, we investigated the efficacy of ketamine in anesthetic dosage in refractory CRPS patients that had failed available standard therapies. METHODS: Twenty ASA I-III patients suffering from refractory CRPS received ketamine in anesthetic dosage over 5 days. Outcome criteria were pain relief, effect on the movement disorder, quality of life, and ability to work at baseline and up to 6 months following treatment. RESULTS: Significant pain relief was observed at 1, 3, and 6 months following treatment (93.5 +/- 11.1%, 89.4 +/- 17.0%, 79.3 +/- 25.3%; P < 0.001). Complete remission from CRPS was observed at 1 month in all patients, at 3 months in 17, and at 6 months in 16 patients. If relapse occurred, significant pain relief was still attained at 3 and 6 months (59.0 +/- 14.7%, P < 0.004; 50.2 +/- 10.6%, P < 0.002). Quality of life, the associated movement disorder, and the ability to work significantly improved in the majority of patients at 3 and 6 months. CONCLUSIONS: This open-label trial suggests benefit in pain reduction, associated CRPS symptoms, improved quality of life and ability to work following anesthetic ketamine in previously refractory CRPS patients. However, a randomized controlled trial will be necessary to prove its efficacy.

Learning disabilities: the need for neuropsychological evaluation.

A learning disability (LD) is a neurobiological disorder that presents as a serious difficulty with reading, arithmetic, and/or written expression that is unexpected, given the individual's intellectual ability. A learning disability is not an emotional disorder nor is it caused by an emotional disorder. If inadequately or improperly evaluated, a learning disability has the potential to impact an individual's functioning adversely and produce functional impairment in multiple life domains. When a learning disability is suspected, an evaluation of neuropsychological abilities is necessary to determine the source of the difficulty as well as the areas of neurocognitive strength that can serve as a foundation for compensatory strategies and treatment options.

The neurocognitive effects of 5 day anesthetic ketamine for the treatment of refractory complex regional pain syndrome.

BACKGROUND: Complex regional pain syndrome I (CRPS) is characterized by severe neuropathic pain that exceeds the severity of an injury and is refractory to traditional treatments. Recent experimental interventions include ketamine infusion therapy. OBJECTIVE: We sought to evaluate the physical, neurocognitive, and emotional effects of extended treatment with anesthetic doses of ketamine in refractory CRPS I patients. METHODS: Nine patients (eight females) received a neuropsychological evaluation pre- and 6 weeks post-treatment that evaluated intellectual and academic abilities, executive functioning/processing speed, attention, learning and memory, and motor functioning. Mood/affect and personality were also evaluated and patients completed an extensive pain questionnaire. RESULTS: There was a marked reduction in the report of both acute and overall pain after treatment. Brief attention and processing speed improved significantly post-treatment, whereas all other cognitive domains remained stable, with the exception of a mild decline in motor strength. CONCLUSIONS: Findings suggest that, at least at a 6-week follow up: (1) deep ketamine therapy is effective for relief of pain CRPS I and (2) there were no adverse cognitive effects of extended treatment with deep ketamine infusion. No definitive conclusions could be drawn about the relationship between mood and personality factors and the presence of CRPS I.

The importance of neuropsychological assessment for the evaluation of childhood learning disorders NAN Policy and Planning Committee.

When children experience learning difficulties, an appropriate evaluation of abilities and skills can provide the foundation for an accurate diagnosis and useful recommendations. When comprehensive information about a child's brain-related strengths and weaknesses is necessary to understand potential sources of the problem and implications for functioning, a neuropsychological evaluation is most often the best choice. This paper was written to help parents, educators, health care providers, and third-party payors to understand the nature of neuropsychological assessment and to choose the type of evaluation that will furnish relevant information for the child's educational planning.

Symptom validity assessment: practice issues and medical necessity NAN policy & planning committee.

Symptom exaggeration or fabrication occurs in a sizeable minority of neuropsychological examinees, with greater prevalence in forensic contexts. Adequate assessment of response validity is essential in order to maximize confidence in the results of neurocognitive and personality measures and in the diagnoses and recommendations that are based on the results. Symptom validity assessment may include specific tests, indices, and observations. The manner in which symptom validity is assessed may vary depending on context but must include a thorough examination of cultural factors. Assessment of response validity, as a component of a medically necessary evaluation, is medically necessary. When determined by the neuropsychologist to be necessary for the assessment of response validity, administration of specific symptom validity tests are also medically necessary.