Earlier disease onset, defined by some authors as <5 years and by others as <7 years, is related to greatest skill disruption, compared with other groups of diabetic children, with lowest scores (4 to 6 points) in mental processing speed, verbal memory, and learning. Differences of this magnitude could be clinically detectable in school performance and may be perceived by children as frustrating and as relative weaknesses compared with their other stronger skills. Slightly lower (2 to 3 points) nonverbal/visual spatial skills, visual memory and learning, and academic achievement are found in children with later disease onset (Ryan 1985, Rovet 1990, Northam 2001, Gaudieri 2008). However, these differences may become greater, up to 7 points, with longer disease duration in adults who had early disease onset (Ferguson 2005).
Longer disease duration, defined as greater than 5 years but usually less than 8 or 9 years in pediatric populations, is related to mildly lower spatial and visual/perceptual skills (2 to 3 points), compared with shorter disease duration under 5 years. Cross-sectional and longitudinal studies indicate that lower verbal memory and failure to make expected developmental gains in vocabulary and other areas of verbal school achievement may be detectable as soon as 2 years after diagnosis with diabetes (Ryan 1985, Rovet 1990, Northam 2001).
Recurrent Severe Hypoglycemia and Chronic Hyperglycemia
Severe hypoglycemia that results in seizures or unconsciousness may have differential age-related effects on the brain, with greater visual spatial and diffuse brain and skill impact on children below the age of 5 or 6 years (Hannonen 2003, Hershey 2003). For older children, controversy exists regarding whether severe hypoglycemia affects verbal memory and, if so, at what glycemic threshold. Clinically, detrimental lasting effects may be seen only with multiple severe hypoglycemic episodes (i.e., over five) or episodes that may interact with a sensitive period of child brain development (i.e., under age 5). At the other end of the glucose continuum, recurrent/protracted hyperglycemia or poorer metabolic control (defined by elevated glycosylated hemoglobin levels >9.0%) is associated with significantly lower general and verbal intellectual ability (7 points) compared with those in better metabolic control (Kaufman 1999, Lynch 2006, Perantie 2008). Significantly poorer visual and verbal learning is found compared with children in better metabolic control (Greer 1996, Lynch 2006), along with significant academic underachievement. In preschool children, protracted hyperglycemia, reflected in higher A1C levels, relates to lower general cognitive ability, poorer receptive language scores, and slower fine motor speed (Patino-Fernandez 2010). In older elementary school–age children, chronic poorer metabolic control has been found to relate to lower academic achievement and poorer attention/memory (Kaufman 1999). Poorer metabolic control may interact with each of the previous disease risk factors and amplify effects.
Acute Disease–Related Findings
Beyond these generally chronic cognitive effects (Gaudieri 2008, Bade-White 2009), evidence of acute, transient cognitive disruption is associated with some diabetes conditions. Acute mild hypoglycemia, defined as >50 mg/dl and <90 mg/dl, is related to transient slowing/disruption in higher-ordered executive functioning (attention, planning, complex decision making) as well as slowed verbal fluency, memory, and motor speed. Accuracy is usually intact (Reich 1990, Ryan 1990, Gonder-Frederick 2009). In the classroom, a hypoglycemic child will have trouble attending to and encoding new information to be recalled. The child may appear sleepy or lethargic. Speed of responding and other cognitive function may not return to normal (prehypoglycemic) levels for up to 45 min once euglycemia is achieved. Despite disrupted blood glucose levels, no evidence of increased rates of attention deficit hyperactivity disorder is reported in association with diabetes. Clinically, attention problems that occur with mild transient hypoglycemia are consistent with the inattentive subtype of attention deficit disorder (Bade-White 2009), although the condition should not be diagnosed if it is secondary to hypoglycemia, i.e., an underlying medical problem. The diagnosis of inattention subtype due to attention deficit disorder would be accurate in the absence of fluctuations in blood glucose, particularly hypoglycemia. Acute transient hypoglycemia that involves seizures or unconsciousness is “severe” and falls under the guidelines for severe recurrent hypoglycemia.
In contrast to hypoglycemia, acute hyperglycemia, defined as a blood glucose level of >300 mg/dl, is relatively unstudied in children, but initial evidence shows an association with slightly lower verbal memory and vocabulary scores as well as reduced speed of cognitive functioning, similar to the effects of acute hypoglycemia (Gonder-Frederick 2009).
Assessment of Neuropsychological Status
Evaluation of neuropsychological status and associated academic performance should follow generally accepted guidelines for identifying children in need of academic assistance. Specialty tests in memory and other neuropsychological skills are available (Lezak 2001). Although tests can be administered by any licensed psychological practitioner, interpretation of results will be more accurate when provided by a trained neuropsychologist or specialist who works with children who have diabetes. Neuropsychological difficulties often co-occur with learning disorders in specific academic areas such as reading or mathematics. State and federal guidelines mandate formal recertification or reassessment of youth diagnosed with learning disorders every three years (Education Rehabilitation Act of 1973). Adoption of testing guidelines also is appropriate with subclinical learning problems. Generally, if a child has learning difficulties of a magnitude that impedes daily or classroom functioning, the youth should be referred to a pediatric or child psychologist. This recommendation includes children who consistently underachieve in a school subject or who have difficulty with memory or other cognitive processing skills. A teacher or parent referral for a psychoeducational screening can help determine the cause of the problem. A screening test of reading, math, and written skills can be administered by an educational specialist. If a problem is found, follow-up comprehensive testing is necessary to qualify for assistive school services. Medical insurance often covers the cost of psychoeducational assessment administered by qualified personnel. Local school psychologists provide another cost-free option, although this latter choice may entail a longer wait for services.
Assessment Considerations
For children with diabetes it is important to first rule out or otherwise address more common medically related issues of school absences, poorer glycemic control, and glucose fluctuations in the classroom, all of which may relate to lower academic achievement as well as memory and attention problems.
During psychological assessment, psychologists should first make sure a child is able to perform blood glucose tests and treat episodes of hypoglycemia. A child should bring a glucose meter to the assessment session, ideally along with a small snack of juice and crackers, in case they should be needed. Glucose testing should occur immediately before psychological testing is begun to maximize optimal performance. Even mild hypoglycemia (blood glucose level >60 and <90 mg/dl) can adversely impact psychological test performance and scores. If moderate or severe hypoglycemia (blood glucose level ≤50 mg/dl) is detected, psychological testing should be rescheduled for another day to allow time for recovery of optimal cognitive status. However, steps should be taken if mild hypoglycemia is suspected during psychological assessment. The assessment should be paused, a blood check should be performed by the child with the child’s own equipment, and a snack should be consumed by the child. Packets of peanut butter crackers and juice boxes provide a good supplement to a test kit. After ingestion of 15 grams of carbohydrate and a 15-min wait, a child should retest his or her blood glucose level to confirm euglycemia, and psychological testing can proceed.
Treatment of Learning Disorders
Treatment recommendations for learning disorders should be selected with consideration of a child’s underlying cognitive strengths and weaknesses as well as the affected academic area. Traditionally, learning problems, if present, may be handled either with remediation strategies that promote acquisition of delayed skills (deficit-focused) or with compensation strategies that focus on residual abilities and environmental strategies to facilitate optimal skill use (strength-focused) (Kanne 2010). Often a combination of techniques is utilized, but most of the treatment literature has studied individuals