HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Correspondence to:

BRIEF COMMUNICATIONS: Claire Flaherty-Craig, Paul Eslinger, Beth Stephens, and Zachary Simmons A rapid screening battery to identify frontal dysfunction in patients with ALS Neurology 2006; 67: 2070-2072 [Abstract] [Full text] [PDF]

Correspondence: Submit a response to this article

Correspondence published:

A rapid screening battery to identify frontal dysfunction in patients with ALS

Paul J Wicks, Sharon Abrahams, P Nigel Leigh, and Laura H Goldstein   (10 March 2007)

Reply from the Authors

Zachary Simmons, Claire Flaherty-Craig, Paul Eslinger, Beth Stephens   (10 March 2007)

A rapid screening battery to identify frontal dysfunction in patients with ALS 10 March 2007
Paul J Wicks, MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry PO 77, Psychology, Institute of Psychiatry, De Crespigny Park, London, SE5 8AF, UK, Sharon Abrahams, P Nigel Leigh, and Laura H Goldstein Send Correspondence to journal: Re: A rapid screening battery to identify frontal dysfunction in patients with ALS p.wicks{at}iop.kcl.ac.uk Paul J Wicks, et al.	We read Flaherty-Craig et al's article with interest. [1] While a brief cognitive screen has the potential to aid clinical judgments, there were three aspects of this study that may warrant further consideration. It appears that the authors used the standard COWA verbal fluency test. Our group has also found verbal fluency to be a sensitive measure of cognitive dysfunction in ALS.[2] We suggested a modification to the verbal fluency test [3] which has been used in subsequent studies. Without such modification, it is not possible to establish the proportion of patients that were deficient for physical versus cognitive causes. Our data indicate that without such a correction for motor/speech problems, verbal fluency deficits may be exaggerated.[2] We would also like to emphasize that there is a difference between statistical significance and clinical significance. This study is one of several recent papers which has used greater than 1.5 SDs below the mean as a cutoff for impairment.[4] As with the Ringholz study, the control group in Flaherty-Craig's article was not matched for years of education and no data is presented for the control group's estimated premorbid IQ. As performance on executive tests is strongly associated with years of education and premorbid IQ, this makes interpretation more difficult. Furthermore, although the authors report that pulmonary function was measured, poor respiratory function does not appear to have been an exclusion criteria. Our group has previously found that performance on cognitive tests can be improved by use of non-invasive ventilation, suggesting that respiratory function may play an important role in the cognitive dysfunction of some individuals with ALS.[5] Considering these factors, we urge some caution in following the authors' inferences from the data. There is a risk that such a small screening battery might inappropriately call into question patients' autonomy in making difficult choices that might conflict with the views of health professionals or family members. While the detection of neuropsychological impairments does raise the possibility of problems with decision-making, screening should be followed by more extensive neuropsychological assessment in addition to careful, patient-specific assessments of the person's capacity to make important decisions about their care, especially when they may involve life-sustaining interventions. References 1. Flaherty-Craig C, Eslinger P, Stephens B, Simmons Z. A rapid screening battery to identify frontal dysfunction in patients with ALS. Neurology 2006;67:2070-2072. 2. Abrahams S, Leigh PN, Harvey A, Vythelingum GN, Grise D, Goldstein LH. Verbal fluency and executive dysfunction in amyotrophic lateral sclerosis (ALS). Neuropsychologia 2000;38:734-747. 3. Abrahams S, Goldstein LH, Al Chalabi A, et al. Relation between cognitive dysfunction and pseudobulbar palsy in amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 1997;62:464-472. 4. Ringholz GM, Appel SH, Bradshaw M, Cooke NA, Mosnik DM, Schulz PE. Prevalence and patterns of cognitive impairment in sporadic ALS. Neurology 2005;65:586-590. 5. Newsom-Davis IC, Lyall RA, Leigh PN, Moxham J, Goldstein LH. The effect of non-invasive positive pressure ventilation (NIPPV) on cognitive function in amyotrophic lateral sclerosis (ALS): a prospective study. J Neurol Neurosurg Psychiatry 2001;71:482-487. Disclosure: The authors report no conflicts of interest.
Reply from the Authors 10 March 2007
Zachary Simmons, Pennsylvania State University Penn State Hershey Medical Center, Dept of Neurology H037, Hershey, PA 17033, Claire Flaherty-Craig, Paul Eslinger, Beth Stephens Send Correspondence to journal: Re: Reply from the Authors zsimmons{at}psu.edu Zachary Simmons, et al.	We thank Dr. Wicks et al for their important observations regarding neurocognitive assessment in ALS and wish to clarify several points. We did not find evidence that motor/speech problems exaggerated the specific verbal associative fluency impairments identified in our ALS sample. We tested this possibility empirically by comparing letter and category (animals) fluency tasks. If motor/speech problems were interfering with the letter fluency task, the mean verbal output per minute should be similar in both tasks. However, category fluency production was significantly higher (Total: t=13.618, p=.0001; Non- Bulbar: t=11.534, p=.0001; Bulbar: t=7.33, p=.0001). Letter fluency results may be signaling specific frontal-related pathophysiology rather than nonspecific motor/speech problems. Volunteer participants for our study were recruited locally and included individuals whose educational and occupational backgrounds were consistent with average intelligence levels. Their mean education level was within 1.3 years of the ALS sample, reflecting technical rather than academic training. Moreover, the ALS total estimated IQ was within the high average range. We do not believe this small educational difference explains the associative fluency deficiencies detected. We agree that careful control for such background variables is imperative, and we are recruiting such a larger control sample for comprehensive analysis. We agree that respiratory function may impact the results of cognitive testing. All of our patients with a forced vital capacity of less than 50% of the predicted value were using nocturnal noninvasive positive pressure ventilation if they were able to tolerate it. The proposed cognitive screening test is not designed to be equivalent to detailed neuropsychological testing. In our ALS clinic, we combine our screen results with clinical interview and the Frontal Behavioral Inventory to provide recommendations to the patient and family. [6] We recommend more detailed testing for patients whose screening results are abnormal. However, patients vary with regard to their ability to undergo further testing and the availability of neuropsychological expertise differs among ALS clinics. The goal of this screen approach is to permit rapid testing of patients with ALS in a busy clinical setting by individuals with a variety of levels of training, so as to alert the ALS team members and family to the likelihood of cognitive dysfunction as they plan care. Our aim is to identify potential cognitive remediation needs of an individual to assure their continued participation in decision making as fully as possible. Reference 6. Kertesz A, Davidson W, Fox H. Frontal Behavioral Inventory: diagnostic criteria for frontal lobe dementia. Can J Neurol Sci 1997;24:29-36. Disclosure: The authors report no conflicts of interest.