vitamin B12 deficiency

We are curious if there could be an underly medical condition with
dementia-like symptoms such as vitamin B12 deficiency.
(Patient's symptoms appear in bold font below. Symptoms are either
current or experienced at one point or another)

Neuropsychiatric Manifestations of Vitamin [B.sub.12] Deficiency:
Peripheral nervous system involvement.
Symmetric peripheral neuropathy, beginning with
symmetric parasthesias of the lower extremities,
can ascend to eventually involve the upper extremities;

hyporeflexia may be present; occasionally autonomic
neuropathy occurs, which can present as orthostatic hypotension.

Spinal cord involvement.
Dorsal column involvement: loss of position and vibration sense,
ataxia,  broad-based gait, and, occasionally, Lhermitte's sign.
Lateral column involvement: weakness and spasticity
(spastic paraparesis), urinary and fecal incontinence,
impotence, hyperreflexia, clonus, and
Babinski reflex may be present.
Subacute combined degeneration.
Spinal cord involvement and peripheral neuropathy.
Visual impairment.
Retrobulbar neuritis, optic atrophy, and pseudotumor cerebri.

Psychiatric manifestations.
Dementia, hallucinations, 
frank ("megaloblastic madness"),
paranoia, depression, violent behavior, and 
change in personality

Above information taken from
http://findarticles.com/p/articles/mi_m0689/is_n6_v41/ai_17913640